Patrick DeCorla-Souza, Tolling and Pricing Program
Manager, FHWA
Lee Munnich, Humphrey Institute, University of
Minnesota
Kenneth Buckeye, Minnesota Department of Transportation
John Doan, SRF Consulting
Center for Innovative Finance Support
Federal Highway Administration
Sixteenth Part of a Webinar Series on Overcoming the Challenges of Congestion Pricing.
Moderator:
Presenters:
Jennifer Symoun
Good afternoon or good morning to those of you to the West. Welcome to today's webinar on Managed lane Access Issues. My name is Jennifer Symoun and I will moderate today's webinar. Please be advised that today's seminar is being recorded.
Before I go any further, I do want to let those of you who are calling into the teleconference for the audio know that you need to mute your computer speakers or else you will be hearing your audio over the computer as well.
I just want to go over the webinar logistics before we start with the first presentation.
If during the presentations you think of a question, please type it into the chat area. Please make sure you send your question to "Everyone" and indicate which presenter your question is for. Presenters will be unable to answer your questions during their presentations, but we will take about 5 minutes following each presentation to address the questions that have been typed in. If we are unable to get through all of the questions in the time allotted we will get written responses from the presenters and send them out with the follow up information.
The PowerPoint presentations used today are available for download from the file download box in the lower right corner of your screen. I would also like to remind you that this session is being recorded. The recording, presentations, and a transcript will be posted to the Tolling and Pricing web site within the next few weeks and I will send out a notice when they are available.
I'd now like to give some brief background information on the topic of today's webinar. Managed lanes are designated lanes or roadways within highway rights-of-way where the flow of traffic is managed by restricting vehicle eligibility, limiting facility access, or and in some cases collecting variably priced tolls. Examples of operating managed lane projects include high-occupancy vehicle (HOV) lanes, Express lanes, high-occupancy toll (HOT) lanes, or exclusive or special use lanes. Each of these concepts offers unique benefits; therefore, careful consideration is given to project goals and objectives in choosing an appropriate lane management strategy or combination of strategies. Project goals may include maximizing throughput, increasing transit use, and providing choices to the traveler.
Today's webinar will cover the subject of managed lane access options, including experiences from existing operational projects and plans for future managed lane systems. Experience with managed lane access on non-barrier separated facilities ranges from full continuous access to access/egress at specific points based upon intersection locations and geometrics. Several operating agencies are currently reviewing and updating their access policies and operations based upon local conditions and results.
Today's webinar will include the following presentations:
John Hourdos, University of Minnesota and Brian Kary, Minnesota DOT will present about the MnPass Access Study. This study compared mobility and safety between I-394, where access is limited through the use of double white lines, and I-35W, where access is more open with minimal areas of double white lines.
Murali Ramanujam, Santa Clara Valley Transportation Authority (Santa Clara County, CA), will discuss VTA's approach to express lanes, approach to provide access to express lanes, and their ongoing experience being an operator of the SR 237 express lanes.
Jennifer Charlebois, Washington State DOT, will discuss WSDOT's experiences with restricted access, its efforts to pilot more open access on existing SR-167 HOT lanes, as well as the plan to evaluate the effectiveness of the demonstration and what that may mean for future managed lanes planning efforts.
So with that, I'll now turn it over to John Hourdos of the University of Minnesota for the first presentation.
John Hourdos
Good afternoon everyone and I hope that you can hear me okay. My name is John Hourdos and I'm the director of the Minnesota Traffic Observatory of the University of Minnesota. The subject of this presentation as Jennifer pointed out is a recently conducted study regarding the effect of HOT lane access design on mobility and safety. We focused on the MnPass HOT lanes on the I-394 and I-35W corridors in Minneapolis, Minnesota in the west and south respectively. But the findings should be applicable to any non-barrier separated HOT facility.
Today we will go through the project objectives, the results from the evaluation, and I will describe a simple tool that we have developed in order to evaluate operations under hypothetically increased HOT lane utilization. I'm going to first pass the gavel to Mr. Brian Kary from MnDOT, who was the project manager and can give us the background of the study.
Brian Kary
Thank you John, this is Brian Kary. I am the freeway operations engineer for MnDOT overseeing the MnPass operations. I just want to provide a quick background here and then I will pass this back to John. We have two HOT lane corridors operating with MnPass, 394 and on the left-hand side here, which opened up in 2005 and 35 on the right hand side which opened up in 2009 or 2010. Probably the biggest difference that you can see in this picture is our access. You can see the access point to the foreground. 394 is probably 80% closed for the double wide and 20% open access. I-35W is more open, pretty much exact opposite of that and 80% open and 20% closed. And when we closed it and saw some highly congested areas, we wanted to perform a study so we got the University of Minnesota on board to look at the performance of these two corridors and see how MnPass operated in terms of safety and mobility. That's pretty much it for the background and I'll pass it back to John.
John Hourdos
Thank you Brian. As Brian pointed there are two design philosophies and they both can have pros and cons. The first objective of this project was to get a handle of the affect that the design alternatives that have mobility and safety. Regardless of other considerations like infrastructure costs and general. So apart from the fact that the I-35W MnPass lane is rather new, both corridors have a very good record in terms of safety. So not too many records to work with. For sure not enough to point a finger to either of the designs. So the first goal of the project was identify some appropriate metrics and use them to among others, to test the hypothesis that the open access design it reduces significantly more near misses that the subject was concerned with. The second objective was to develop a methodology and tools to assist in the design of corridors following either design. So the case of the open access we developed the tool to evaluate hypothetical conditions since what works today may not work as well in the future. And in the case of restrictive access like I-394 were still waiting on the tool of optimization and size of the zones based on the actual graphic measurements. This is work is still ongoing so I will not go through this in this presentation.
So our project is based on the generation of video records connected from all available cameras in each corridor and we complemented our observation with some of our own portable surveillance systems by the Observatory to fill in gaps along the road. Although our observations cover the entire length of the facilities, we focused our attention to areas where the general purpose lanes are congested. This is where the most disruption between the two lanes is happening.
All lane changes to and from the HOT lanes were identified and counted for the video. And we decided to use the activity a surrogate measures. Frequency is a good measure of mobility since the higher frequency indicates less time under I'm congested conditions and therefore reduced mobility. On the other hand, shoulder length can be used as a measure of safety, given that the longer the chain of drivers having to react and reduce their speed, the higher the probability of the red collision.
So here if we can play the video, Jennifer.
Before the video comes up you can see here on I-35W that the white SUV was leaving a completely stopped lane going to the left and entering the HOT lane.
Jennifer Symoun
It looks like we may be in a situation where the video is not currently working.
John Hourdos
Well I see it. Well you can see the steel frame here and the white SUV is entering the lane from almost zero speed and entering the lane that is currently going around 55 miles an hour. So the next frame shows us the white truck that is behind it had to considerably reduce its speed in order to allow the white SUV to merge and three additional cars had to reduce their speed.
In this case the reduction of speed was caused by the inappropriate lane change of the white SUV. So to summarize, we counted as inappropriate any lane changes that resulted in the disruption of the flow and from leaving the lane.
The next example is from 394. This of the reversed situation. The HOT lane is almost stopped and the vehicle in the HOT lane , since this is the only open access area in this section, would like to leave the HOT lanes but because there's no room it delays and stops all of the vehicles that is following it, again generating a shockwave behind it. So most cases when we measure the shockwave, you can have a shockwave of just one vehicle if only one vehicle had to reduce its speed because of the vehicle that makes the lane change. It is a rather extreme definition but on the conservative side
So this slide basically shows the two corridors of I-35W and I-394 and one is considerably longer as the slide shows but I had to squeeze it to fit both in one slide so I removed some of the areas and a reduced the scale. The red dots represent the location of cameras that we can currently record the video from over several days in August 2012. The corridors were divided into zones of interest so basically we included in the zone as a single area of congestion and the general-purpose lanes.
It should be good to not hear that the two quarters have considerably different demand patterns and most of it is concentrating on three interchanges of the 394 and I35w where the I35W has much higher demand and is more spread out.
So now to get to the meat of the results, this is an example of the results slide from zone number one. Zone number one is at the beginning of the northbound direction of the HOT lane there at the beginning the time of the study but now the limits that should be extended further to the south. The frame on the top left, you can see on the far end, the congested general-purpose lanes in the direction of interest the leftmost lane of the direction is the HOT lane. We were basically counting all of the lane changes that happened from the general-purpose lanes to the HOT and in reverse. The graph on the top right, then you have the average count of the appropriate lane changes of observation deck and the four cameras that actually covered the zone. So most of the inappropriately changes are happening at the first upstream camera 608 which is closest to the interchange that is actually causing the bottleneck on the general-purpose lanes. The figure under this and the blue line shows the percent of inappropriately changes in the overall lane changes aggregated every 15 min. The solid line is the meanwhile the best lines represent one standard deviation around the mean. So for example we see that at the peak of around 7 AM, 70% of the inappropriate lane changes demonstrated the disturbance. The following graph shows the disturbance may have been just one vehicle slowing down. To quantify the effect on the graphic, the next graph represents the percent of shockwave over the entire 15 min. volume of the HOT. In this case we can see that around 7 AM, almost 50% of vehicles of the HOT weren't what involved in a shockwave. You can see that the shape of the two curves is not the same since the smaller amount of inappropriate changes may generate longer shockwaves if the speed drop is much more abrupt or if the density of the HOT lane is higher at that point. Finally the point on the left bottom of the slide designs the observed shockwave characteristics. The red line inside the box is the medium shockwave length observed. The top and bottom of the box for present the 25th at 75th percentiles respectively while the whiskers extend the most extreme length that are not considered outliers. So can see that the medium length of the shockwave is about 3 1/2 or four vehicles, while the shockwaves can extend all the way up to nine vehicles.
The next slide shows the same information for zone four which is on the other end of the northbound direction on the HOT lane. This of the biggest bottleneck of the corridor and the congestion was captured on the larger number of cameras so you can see here for seven cameras that were involved in this area. But again, we see that most of the inappropriately changes are concentrated to maybe two or three locations.
From the graphs with a higher number of vehicles affected by the shockwaves but the disruptions happen on a shorter time interval. It is good to note that the density of the HOT lane in this location is much higher than in zone one. Disruptions are happening in this case, twice a day. Since both the a.m. and p.m. periods are congested.
From the box we can see that although the medium shockwave length has not changed much, longer shockwaves are more often observed so the medium amended approximately two or three and maybe four vehicles but the 75th percentile has raised above five vehicles and have observed monolayer shockwaves extending into 12 weeks.
This slide is basically a summary of all of the observations that we had on 35 W and I just showed you the previous two slides had only two of the worst zones of the word couple more. But you can see that in general, most of the locations, the average shockwave is approximately less than four vehicles, while in the extreme cases we had shockwaves that are going out most 12 to 14 vehicles long. Not terribly long shockwaves.
So now moving to I-394, around Louisiana Avenue where this slide is focused. From the graph we can see disturbance activity, both in the a.m. and p.m. peak periods. We observed fewer inappropriate changes in this 15 min. period. For example, in the a.m., up to 94, the presented 10% of the lane changes well in zone one is we saw before was 30%. Although the disturbances or fewer in number, the effect is similar percent of the volume. And interestingly, if we focus on the [indiscernible], we can see that the median length of the shockwaves climbed a little, but is similar to the worst location on I-35W. This can better be seen in the next slide. We have the three most troublesome locations of I-35W the first and the last box is the I-394. You can see that they're very comparable in terms of the shockwave. Just takes with I-394 just the median a little bit higher. Again the central mark is the median and the edges of the box are the 75th and the 25th percentile of shockwave length.
Now to bring this all together, from our observations today, we believe that each design works well for its respective freeway. The shockwave activity is similar between sites. That allowed access to regions and the more lane changes, but the lower percent of them generate disturbances. Regardless, these fewer disturbances are bigger as compared to the ones observed on I-35W. Slightly bigger but still bigger. The design works well since 90% of the demand comes from three distinct interchanges and that's where you locate the gates. This is not the case in the I-35W with the spread of more interchanges. Being more congested they presented disturbances on more than one location but in focusing on locations near more major interchanges. So it is important to note that even though they had followed the restricted access design, these locations most likely would still have been the gates assigned to them.
These are the locations where in the future we may have to restrict access to high congestion or reduce the price to reduce density. My presentations will go a little fast on the last subject which is the tool that shows us what can happen if the density on the HOT lane is increased. It was focused on congestion and the three worst locations of I-35W. And basically, we designed a model that simulates shockwaves given measurements from the field. We have a model that produces shockwave length distribution given the certain parameters. So when you execute the simulation, you give to the model the general-purpose speeds so that the speed drop generated by the late changes is realistic. And we also give the lane density measurement in the time series of the density of this lane.
From this we can actually replicate the shockwaves that we've seen in the reality. But we also decides the loading recognition that allows us to increase in density. So here is the validation of the model and you can see that we captured well observed shockwaves. We are a little on the conservative side because it presented the longer shockwaves. But they generally match well.
Now, this slide is I think it will be my last slide in this basically shows us what is the shockwave activity in the 50% increase in density and 35% all the way to 150. We can see that if we actually increase the utilization of the general-purpose lane or the HOT lane by 50%, then the shockwaves don't change much. But there are some very long shockwaves that are appearing. But it 75% were of a very prominent peak of shockwaves up by 35 vehicles long. All the way to the end of 150% I would have the total breakdown on the flow of the HOT lane. So there is room and the final slide shows you the accumulative distributions of these shockwaves. We can see that there is room to low the lane more into would reach a level where the long shockwaves are going to be prominent and more frequent. So can see here that even if you go to 100% it takes only about 40% of these shockwaves will be greater than 20 vehicles length.
That's what I have today. Thank you for listening.
Jennifer Symoun
All right thank you John and Brian. We are not going to take about 5 minutes for questions. So let's start with the first question. Are you using ramp metering and/or speed harmonization in the congested roadway?
John Hourdos
Yes. 35 W is using both randomization and speed harmonization. Before it was only using metering.
Jennifer Symoun
Okay thank you. The next question is can the number and percentage of inappropriate lane changes also be also compared to the GP and ML lane volume or density at each time slice?
John Hourdos
Yes. If I understand the question correctly, yes. The number and percent of inappropriately changes tracks well the density and volume of each time slice. Although, that is why we included the percent of vehicles involved in the shockwaves to basically try to normalize this and show the amount of vehicles that are actually affect it by this disturbance. The label has a very low volume during those times because it's congested. And the manage lane, since is not directly related, could have lower volume, the South of the higher volume in the North.
Jennifer Symoun
All right. And can you please define inappropriate lane changes?
John Hourdos
Yes for the purposes of the project as I said, inappropriate lane changes are any lane changes that are causing the driver on the receiving lane to adjust speed. So if a vehicle leaves the general-purpose lane, the lower speed than what the HOT lane has at the moment and if the vehicle has to reduce its speed to reduce the avoid a collision and allow the vehicle that just change lanes to accelerate and keep going, that is an inappropriate change.
Jennifer Symoun
Do the models apply to HOV lanes or just HOT?
John Hourdos
Well technically speaking, the models to apply to both. It does not matter if it is HOV or HOT. Any time that you have access issues and if you have lane changes from a congested general-purpose lane to an uncontested HOV or HOT, the model applies. This important to note though the HOT, the density on the HOT is controlled by the pricing algorithm. In a sense we are expecting to control the density on it. While in the HOV, the density can be anything the demand.
Jennifer Symoun
All right. Is any law enforcement used?
Brian Kary
I will take that one and I think there was a similar question about that on open access facilities about what observations have made regarding toll avoidance of violations. We really have not seen anything within the two corridors. I think generally speaking when speeds are higher then it is probably more likely that people might try to avoid the toll reader because it easy for them to jockey back and forth between general-purpose on the HOT lane. But if the general-purpose lanes are broken down and the tolls are higher, we are probably more concerned about that and then it really becomes kind of impossible to do that because it just difficult to make that frequently change. The other thing is that we have not seen much difference in terms of 394W to 94 because of people attempting to avoid a toll, they probably don't care about the double white line. They probably just drive over the two.
Jennifer Symoun
All right thank you. We will now move onto the next presentation but feel free to continue typing in questions. Thank you John and Brian. We are now going to move onto our next presentation, which will be given by Murali Ramanujam of the Santa Clara Valley Transportation Authority in Santa Clara County, CA.
Murali Ramanujam
Thank you Jennifer. I'd like to share little bit of experience that we have had in some projects that we are working on.
Today I wanted to share little bit about the express lane program we are undertaking and it is a program that was approved back in 2008. That consists of two corridors with the Highway 237 putting the East-West direction in Silicon Valley and we also have 85 and 101 the North South direction coming through the Santa Clara County, which is really located in the southern part of the area.
I think it is worthwhile to help highlight the fact that this express lane program also consists of almost half of the total length of this express lane project. So that might be a slightly unique feature compared to some of the other express lane projects.
So when we actually started with the express lane project, at that time, there were two types of access arrangements that we were considering. One was the past project that we just heard about that has the double white line painted buffer which was also kind of similar to the Southern California carpool lane system that had this double white line separating the general-purpose lane and the carpool lane or the express lane.
This is kind of different from the Bay Area here where we actually have contiguous lines. At the same time, the first Bay Area express lanes project, led by the Alameda County transportation commission, this was the express lanes project. So at this point this express lane project had a continuation of a margin lane to get into the express lane or to exit with the bottom left picture
So as we move forward, we decided to follow the MnPass approach. As you can see here, the express lane project where we chose the double white lines that separate the general-purpose lanes. But moving forward, there are different types of access arrangements being considered in the Bay Area. VTA is continuing to want to move forward.
There is also continuous access arrangement being considered in the Bay Area. Mainly by the Alameda County Commission, which is a couple of other projects in addition to the 680 express lane. We are about to implement the 580 express lane project and there are also five other express lane projects through the Metropolitan Transportation Commission which is the metropolitan planning organization in the Bay Area.
Here basically what we are talking about is the limited access any of the painted buffers separating the two adjacent lanes between the express lanes in the general-purpose lanes. And we do have openings at designated locations so the traffic can weave in and out of these lanes.
Then as part of the striping this is the double white line for the most part work we are not using any channels but here there are pictures of the Miami express lane and I believe that was the 91 express lanes in Southern California that does the same. For the express lane is actually separated the general-purpose lane using the channels in addition to [indiscernible]. So for the continuous access, it is going to be remaining the same as what you have out there that for example the carpool lane separated from the general-purpose lane like here in the Bay Area. That would be minimal or no change to the striping. But the real change is the greater amount of electronic tool system equipment to be placed at different intervals throughout the express lane.
Our approach has generally been this way. But when we have the express lane corridor, we look at the entire corridor. And we try to identify the major bottleneck locations. So based on our express lanes experiences, these other key locations we have the major bottlenecks and where you do want to have a separation between the two adjacent lanes by introducing the double white lines. Because when you do that, what we are seeing is that they need to achieve that reliability and the corridor, which is a key element of any express lane project.
As far as other locations other than the non-bottleneck locations, I think that there is a lot more opportunity to do it any which way you want. But I think the major big rocks that we want to deal with in trying to address where the opening should be or whether the double white line should be is to identify where the major bottlenecks are and in those locations try to introduce this separation between the two adjacent traffic flows.
So that they can have moving rather slowly without having too much occurring. So it may not be as long as it needs to be. So some of this is currently undertaking the preliminary design for some of our future express lane projects we are already looking at access points that will be well over 1 mile long.
So I think at the end of the day when you look at these to access arrangements. If you look at the continuous access arrangement, you are looking at a scenario we have a lot of electronic tool systems and less striping as part of the project. Or if you look at the limited access as was mentioned earlier in the presentation, maybe have a little less electronic system and maybe about 20% of that. And it is more 80% striping. And I guess where we are, with the introduction of the 237 express lanes in moving forward is that we are open to have a little bit of both I should say. So the optimal solution will really be depending on what you really see in the field.
So the approach that we have been using so far is this. We are kind of a hierarchical approach to see where the access point should be located. So, looking at the network systems that we have, we always look at where are the key system interchanges and allowing traffic to move from one highway to another and ensure that those access points are provided where they go.
And then, apart from that, we also have expressway system locally here of about six or seven expressway systems which carry about 60,000 to 70,000 traffic volumes and that's the system whereby it has a lot of over crossings and underpasses. Allowing for traffic to travel through the area rather quickly.
So we try to look at accommodating access to that system. And then thirdly, we look at major arterials and look at the where the regional attractors are and providing access to airports or major employers and so on and so forth.
So once we have selected the location, then really we are talking about going through a process as to how to fine tune the location. If you start off first by using the design status and see what is the minimum distance required, certain on-ramp or trying to reach a certain off-ramp from the express lane. And you would find the location and then check if the particular location if you can fit in this access opening geometrically.
If that happens to be true, then you can look at whether and how that opening plays out in relation to the general-purpose lane. If it is a location where there is heavy traffic or congestion or if the cause is lined up, that is no point providing an opening to that area because you may end up not being able to exit to the general-purpose lane that would cause a key within the express lane ourselves.
So you go through this process trying to place them in the best location possible. But at the end of the day, you do find that this is a very challenging task to do especially in a very highly organized area. So when I talked a little about the express lanes, that's actually a project located in the system and to change on SR 237 and it is located in the golden triangle area, bordered by highway SR 237 . On the top the Highway 101 is at the bottom. There are a lot of major players here and put a want to say is that the end result of this express lanes project that we find that we can do congestion pricing with the HOV lane corridors. Most of the access points, again we looked at , this is the carpool to the direct connector that comes out of the north-south direction. And what we looked right next to the system is the interchange with the other interchange located nearby. And between the segments is very much the bottleneck that was occurring due to multiple merging and movement occurring there.
So when we did introduce the double white line with the general-purpose lane, express lanes, we saw that there was smoother traffic flow through the segment, which was accepted in travel time savings.
That has been our mantra, that all have travel time savings because when you do that many of the other issues tend to go away. Another thing that I like to highlight is of the location of the express lanes, if you're looking in the East West direction or more so the West direction that the redline that you are seeing which is where the double white line segments are. And then, as you go further west, you see the orange or yellow line there. But we are working with the California Department of Transportation, what we found is that if we ended the double white line, and I don't know if you can see that. But that there are two other closely spaced interchanges where there will be a lot of traffic exiting to those locations.
As a result, the access arrangement that we actually had was a line extending almost 3 miles. So one can argue that it's not dissimilar to have a continuous access would work but this design was really based on looking out what is really happening at the level and accommodating and opening based on that. We are currently embarking on the second phase of the express lanes project. We were fortunate enough to get some grant money of the $1.6 million from FHWA as part of the program. And that is currently where we are right now.
I like to conclude by saying that at the end of the day, I think the public will want to see the design option with access arrangement that makes sense based on existing constraints in the field conditions. So trying to understand and providing a correct access arrangement configuration continues to be part of an evolving area.
So with that, I will end my presentation. Thank you.
Jennifer Symoun
All right thank you and again we will take about 5 minutes for questions. Some of these questions have been answered directly the box but we will go through a few of them. Let's see. Have you observed drivers who aren't eligible to enter the HOT lane using it as a passing lane in places where they know there are no readers?
Murali Ramanujam
Yes we do see that and it is happening more on the SR 237 express lanes in the eastbound direction during the peak period where people enter the express lane and you have that before the double white lines with actually start. So during the peak period with the congestion is really heavy, there are some people who try to do that. And we can see that happening.
Jennifer Symoun
What is the required spacing of the transponder readers in the continuous access and its impact on the overall cost of the project?
Murali Ramanujam
That's a good question and I'm not sure I'm the best person to answer that because we have not done any continuous access projects. But based on my limited knowledge, this might be about 1 1/2 miles or 1 mile in spacing. But I cannot really talk about how the cost relates to that. But I think one could look at it in this way. If we are trying to do and implement thing to buffer up front, and if there is a cost that you might incur upfront to deliver the project. But if we go for installing an electronic toll system equipment as part of the project, then you may have more recurring cost on the line, because any time you have equipment, we have maintenance and some sort of lifecycle attached to that.
Jennifer Symoun
All right. Let's see here. Are access to, and egress from, managed lanes always coincident?
Murali Ramanujam
I'm not sure I follow the question.
Jennifer Symoun
Sure if the person asking the question would like to clarify that one. Can you provide your annual operating cost per mile of express lane?
Murali Ramanujam
Annual operating cost per mile. Well I can say this. It cost us about half a million dollars. This is a very small project basically because the core aspect of the projects with converting a carpool to carpool direct connector project that it is very short distance from 4 miles long. So our cost was slightly less than $600,000 operating for the first fiscal year. And we grossed about $1 million in the last year. This can vary quite a bit if you have continuous access but not have data on that network
Jennifer Symoun
Okay. One more question here. What are the total time savings for users on the HOT lane versus the GP lanes?
Murali Ramanujam
When we initially opened about 20+ months ago we then saw time savings up to 20 min. And since then, traffic has grown in the area and regionally. And now we're seeing up to 15 min. But the point I would make is a good 80% to 90% of those trouble time savings is coming from those locations. And hence, if the focus is on bottleneck locations, you will ensure that the travel time savings is a very important component of the calling your project successful to the public
Jennifer Symoun
All right thank you. Well at this point, we are going to move on to the last presentation. I think that Joe has provided a lot of responses in the chat box to the questions, but Murali if you want to continue responding to anything in there please feel free. We'll move onto our final presentation will be given by Jennifer Charlebois of the Washington State Department of Transportation. Jennifer I will bring up your presentation and you can go ahead.
Jennifer Charlebois
Thanks Jennifer. Good afternoon everyone. I will talk a little bit about the WSDOT plan for continuous access on our SR-167 corridor. First I'll start with a brief discussion on background information on our HOV system. So we have a little over 300 mile HOV system in the Puget Sound region. This provides for reliable transit service as well as an incentive for carpoolers. The system is for the most part continuous access so WSDOT has a lot of experience operationally with continuous access facilities. Our HOV system is however, very well used. It so well used that in some cases it is starting to break down. As you can see on the slide, there are several sections where the HOV lane system is not meeting the speed and reliability objectives that we have set. Mainly 45 miles per hour 90% of the time during peak periods. While generally our HOV system provides travel time advantage over the adjacent GP lanes, we feel that they could be managed more efficiently in some areas. Because we have some areas that are overly congested in peak periods and others that are underutilized.
I think most of you are familiar with the use of the express lanes as the right solution for this and a way to more efficiently manage our network. Pricing our managed lane facilities through the use of express toll lanes will allow us to continue to provide speed and travel time reliability, while also allowing us to continue to provide reliability for transit and an incentive for carpooling, while also offering a reliable trip to paying customers, all while maximizing the person throughput of the lanes.
WSDOT's first opportunity to convert an HOV lane to an express lane was with a 4-year pilot project on SR167 in Southern King County. We opened the system in May of 2008. Just a note that you may hear this referred to this as a HOT lane and an express toll lane interchangeably. We are transitioning here our terminology to express toll lanes.
We chose SR167 for the pilot project because it was a highly congested route in the peak periods with an underutilized HOV lane, that would clearly provide a benefit if operated as an Express Toll Lane.
SR167's express toll lanes are free for buses and vanpools and carpools and motorcycles. There is a single express toll lane each direction. Solo drivers pay a single toll to travel any distance on 10-mile route. We do convey the toll rate to each driver via a variable message for each access location. The system uses designated access points. That express toll lane is separated from the general purpose lanes by a double white line, which is illegal to cross.
There are 10 access points in each direction. And there is a transponder requirement. Drivers who are not in carpools or vanpools require a transponder to pay the fee. We have no photo enforcement of the corridor.
Overall the SR-167 system has operated successfully over the last five years. The HOT lanes are operating with the toll revenue continuing to exceed are operating cost. We have seen steady increases in the number of drivers paying to use the lanes year after year. When we were planning the SR-167 HOT conversion in 2006 at the time our thinking was designated access was needed to minimize toll avoidance. So that was the type of access that was put in place. But as we look forward to expanding our express toll lane system throughout the region we are looking for ways to continue to improve.
So where are we in looking at starting continuous access on SR-167? As I mentioned, we think that the system is operating successfully but we want to continue to look at ways to make the system more efficient. The number one complaint from drivers of the system is usually regarding the designated access. In a survey of our existing customers, 40% of them responded that they were unsatisfied with the current access restrictions. We tend to hear from transit operators that the coaches will enter the freeway from the right and merge over to the second general-purpose lane and then have to sit in stop and go traffic until they can get to an access point to enter the express toll lane.
In 2011 the University of Washington conducted an evaluation of the SR-167 HOT lane violation patterns. They concluded that drivers do not predominantly violate the restricted access to avoid the toll, but rather to avoid the congestion. Drivers were observed violating the restricted access by crossing the double white line to enter the HOT lane at the point where the GP lane becomes congested (or the back of the GP queue).
Also, as we look at the potential to convert some of our existing HOV systems to express toll lanes, we think there are several design issues that we are facing the could potentially be solved with continuous access.
First, many of our current facilities have congestion patterns that are geographically in different locations in the morning versus evening and versus weekends. Continuous access has potential to allow customers to make their buy-in choice more flexibly in response to changing congestion patterns.
We are also looking at express lane applications on facilities with extremely constricted right-of-way, such as our I-5 and I-90 corridors. Continuous access would allow a priced lane on a facility without any additional roadway width, and/or the potential for a second express lane with variable or dynamic use.
Lastly, the use of continuous access would allow us to further contemplate the use of dynamically assigned express toll lanes. So this might be an express toll lane that might operate for certain hours of the day and go back to GP other hours of the day.
In 2012 we applied for and received a Federal Value Pricing Program grant to demonstrate more-open access on the SR167 corridor. The goal of the project is really to validate the revenue and toll evasion effects of more open access to express toll lanes. And we want to understand customer responses and understand the attitudes and concerns about continuous access. We also want to understand our ability to communicate a dynamic toll point that is not displayed at the exact point of entry. And really we want to prove the feasibility of potential innovative express toll lane treatments that will require more continuous access
We have three main project elements. Public information and outreach, restriping and the related facility changes, and the before-and-after evaluation. The first project element is public information and outreach. We feel it is really important to reach to the drivers who use this facility every day and explain that we've listened to their feedback and are making this change to make it easier to enter and exit the HOT lanes. We wanted to make it clear that we're making this change in an effort to find new ways to make our roadways more efficient, while maintaining safety. And we're planning direct outreach to our existing good to go customers as well as taking advantage of any earned media that might come about. Also we will be planning some agency outreach. First to work with the transit operators to ensure they are aware of the change and allow them to make any necessary changes to route planning or route times. We will also be working with the Washington State Patrol, which currently enforces both carpool violations, as well as violations of the double white lines. We will work with them to make sure that they understand the message to drivers as well.
The next project is the actual restriping and facility changes. We will be advertising a small design-bid-build project for the work. The work really consists of grinding to remove the second gore stripe leaving one continuous solid white line. The existing HOT lane is 12-feet wide and we'll be removing the stripe on the left, resulting in a 14-foot wide express toll lane adjacent to a 12-foot GP lane. We expect the work effort to be minimal and take two or three weeks to complete.
In addition to the striping changes, we will also be removing the sign that discusses the access points. You'll see that we currently have 41 "Illegal to cross double white line" signs in the corridor. Many of those were added early after the system went live because we saw so many folks violating and to aid with enforcement. We will also be removing or modifying signing that discusses access locations.
You may hear me discuss near continuous access or more open access. As I mentioned earlier, WSDOT does operate in an existing system that is the most part operated with open access. But even in our HOV system we do have some occasions we have chosen to restrict access for safety or operational reasons, so we plan to take the same approach with this system.
We did look at opportunities or places that may be necessary to restrict access, but we were looking at two different types of operational issues. The first one was the areas with the heavy weaving or merging pattern, this may have caused us to restrict access for safety concerns. An analysis of the corridor did not turn up any of these areas, so we are not going to be restricting access for that reason in the corridor.
The second area that we looked at was at the end of each system in each direction. As you know from this graphic, the HOT lane designation in each direction continues past the point of the last toll point. There are no "close-out readers" located at the ends of the system. To prevent drivers from entering the lane after the last toll point, we've decided to restrict access at both ends of the system. So we will be restricting access but the last to point to each direction and the end of the express toll lane designation.
I also want you to know that for these demonstration projects, we are really only changing the signing and stripping. We're not making any changes to the two point locations, or to any of the toll equipment that is currently located in the corridor. If we were building a new express toll lane system of continuous access, then we may think differently about how we want to locate or where we want to locate the toll equipment. We are hoping that this demonstration will take us a little bit more about how we want to put that in the future.
So the last project element is the before and after evaluation. WSDOT is going to be contacting with the Washington State Transportation Center at the University Washington to conduct an evaluation. We will be collecting data for a period of about six months prior to the operational change and comparing that data against the same six months of the following year.
The evaluation will focus on several areas. First of which is safety. We will be looking at both driver perception of safety via surveys with our existing customers, and also looking at an examination of crash history or trends and crash information/
Next we will be looking at revenue collection and will be looking both at any changes to total revenue collection, as well as any changes to the time of day pricing patterns. So are we seeing higher or lower prices on a per trip basis for any reason?
I think the one that most people would be interested is the toll evasion, which we are really looking for specific kinds of behavior. We will be looking for drivers who exit the lanes just prior to the toll point and then reenter after the toll point, essentially evading the toll. And secondly, we will be looking at drivers who use the express toll lanes as a passing lane around other drivers in the general-purpose lane. In terms of methodology, we have considered working with the video surveillance to observe this type of driver behavior, but we do have some holes in our system in the corridor and also that type of methodology might be overly costly. So we are going to take a more statistical analysis approach. We are going to look at two different types of information. We are going to track the percentage of vehicles that do not have tags passing each of the 12 points. Then if the percentage increases, it could be interpreted as a likely increase in violators. Secondly, we will be tracking overall traffic volumes throughout the corridor to determine if the volume changes at the detection locations are consistent with the volume changes between the detection locations. If these two changes are relatively consistent then we can assume that there's not been increase in the toll evasion.
We will also look at speed and reliability of both the express toll lanes as well as the GP lane. We will be trying to learn more about customer attitudes, by surveying our existing customers and we are interested to find out if customers are aware of the change, how they feel about it, and perceptions of safety.
Lastly we want to look at any effect on transit operations. We will be interviewing our transit operators and will analyze any changes in transit schedules. And we will be attempting to determine if there has been any changes and reliability of operations.
The next steps for this work are, we will be advertising the construction project early in this next year and making the operational change this coming summer. Data collection will be complete in mid-2015 and then we will be looking to finalize the evaluation in the fall of 2015.
We are really looking forward to learning more about the results of this project and we think it will help inform the next evolution of the express toll lane projects here in the Puget Sound region. If continuous access is successful in the demonstration it would allow us to continue to study options for dynamic lane assignment and potentially reduce the cost and construction times associated with future HOV lanes or toll lane conversions. That is the end of what I have for you today. I would love to hear any questions.
Jennifer Symoun
All right thank you. We will go to questions now. So the first question here and I think this may have been a misunderstanding but I just want to get it cleared up was that if there were no transponders, how did you manage tolls?
Jennifer Charlebois
There are transponders. Anyone paying to use the lane needs to have a transponder in the vehicle.
Jennifer Symoun
All right. How would you identify toll violators, single occupancy vehicles on Express/HOT lane?
Jennifer Charlebois
Our Washington State Patrol does that for us. We have beacons located at every toll point and the beginning and the system reads the transponder. So at this point our troopers look at the vehicle and make sure the correct number of people is in the car and pull anyone over who was not following the carpool requirements appropriately. And then they enforce double white line crossings as well.
Jennifer Symoun
All right. How will continuous access to the HOT lane help transit travel time- this was a concern in your earlier slides. I have trouble understanding continuous merging helping bus travel time.
Jennifer Charlebois
Maybe I can delve more into what I noted already. But what we have heard from our transit operators is that they will merge onto the freeway from the right side. They spend a lot of time especially in stop and go traffic for the GP lane. If access is continuous they can enter the express toll lane and hopefully have a more free flowing trip. But in the case of designated access they are stuck in the GP lane until they could reach that access point into the express toll lane.
Jennifer Symoun
All right let's see here. How much does it cost to enforce this corridor annually? Are you using law enforcement or technology for enforcement?
Jennifer Charlebois
Let's focus on the cost for enforcement , I have Tyler in the room with me and this is the cost for enforcement. It is $140,000 per year, about $10,000 per month.
Jennifer Symoun
All right thank you. Let's see here. Are you studying potential of continuous AND limited for the future, limited as defined in last presentation?
Jennifer Charlebois
We are looking into combination of continuous and designated access. And the project is to discuss continuous access. But there may be reasons why we would need the concentrated restricted access, I think that's the approach we take going forward.
Jennifer Symoun
All right. Let's see. With heavy HOV volumes currently, is there concern about being able to control LOS (pricing out vehicles if needed) of HOT lanes if continuous access is provided?
Jennifer Charlebois
I'm guessing that the assumption of the person asking the question would be the continuous access would increase the number of users in the lane. If that's the case, it was to look at other ways of managing and continuing operations for efficient operations of the facility, either by adjusting the pricing and I suppose there's a potential for adjusting the occupancy requirement if needed.
Jennifer Symoun
All right. We have a few questions here that are for all of the presenters so I will put it out there for everybody to answer and get everybody's opinion. Let's see here. The first question we have here is, with continuous access, are there safety problems when there is a significant speed differential between the ELs and the general traffic lanes? I will let anyone of the jump in if you want to answer that.
Jennifer Charlebois
This is Jennifer and I can just know that is definitely one of the concerns that we are wanting to understand more about. That's where we are including that in our valuation.
Murali Ramanujam
This is Murali Ramanujam. I'm not sure if we have any clear data. But currently because we have up to give this lane approach for the car pooling system of the Bay area, that is kind of something that happened now. And I also believe maybe there was the California transportation study done in the past. But I think that whether it is a limited access or continuous access approach, I think in terms of safety, they both seem to work about the same work
Brian Kary
That was pretty much what our study was looking at work so we didn't really see any differences in terms of safety issues then with more closed access or restricted access.
Jennifer Symoun
All right thank you. Another question for all presenters I don't know if any of you have any thoughts on this, but what impact will connected vehicles have on your overall load capacity and the need for HOT lanes?
John Hourdos
I can take a stab at this but it is a completely off the top of my head stab. The connected vehicles, or the application of connected vehicles they could have an impact here is the electronic emergency braking. In which case, you're going to have if you have the shockwaves that we have observed, you have a smaller probability of a driver running into another driver. Because they know about the shockwave for the accuracy the vehicle in front of them slowing down.
Potentially, if the system works well and another application could come in alerting you of the vehicle's intention to get into the lane and cut you off. But that is not an application of connected vehicles as it stands right now. So don't know if that is something that should happen in the future. But other than that, I don't see any other impacts on the conditions that we observed.
Jennifer Symoun
All right. Another question open out to all of you is are you aware of any projects that have experienced increased VEHICULAR throughput with express toll lanes?
Murali Ramanujam
This is Murali Ramanujam from VTA. Yes we have seen increased vehicle throughput after implementing the express lanes project. I don't have the numbers handy with me, but I can definitely provide that to the group as part of the answers later on.
Jennifer Charlebois
This is Jennifer. Same here. We have definitely seen increased throughput on our system without the figures in front of me but I can provide them.
John Hourdos
The same for Minnesota. We are converting underutilized carpool into the HOT lanes sourcing added throughput.
Jennifer Symoun
Thank you. Jennifer I believe this question was for you. Did you find that enforcement might cause disruption to the traffic since you do not have much room in the HOT lane?
Jennifer Charlebois
Yes. We worked with the troopers quite a bit. They have concerns about enforcing carpool violations during peak periods because it does disrupt the flow of traffic. So they have to make that call and really enforce it when it makes most sense for them.
Jennifer Symoun
Okay. Here's another question for everybody. Recognizing the basic objective being to address congestion (whether generally or "choke points"), what has been the basis for establishing the length of these various projects? What was considered the minimum distance needed--and was that based on revenue return and/or cost to build versus amount of reduction in congestion?
Murali Ramanujam
This is Murali Ramanujam from VTA. I think we looked at it as any one distance or whatever. But as a general rule of thumb, I think over the years we find that a lot of the express lanes projects have a distance of plus or minus 10 miles. And the express lanes project has been much shorter than that. They may be 7 miles in one direction or 4 miles in another direction. And again, I think the actual limits of the project changed for the express lanes. For example from 4 miles in one direction to 7 miles. And that based on the conditions. So we always have to take into consideration what is going to happen at the project at a certain location. I think that is the challenge that we see moving forward. So we are undertaking projects that are much longer in length like the highway 5 Express lane. It is about 24 miles long and the Highway 101 express lane is about 34 miles long. And a lot of times, the extent of the project we could really deliver is diminished by funding.
Jennifer Symoun
Okay thank you. John, Brian, or Jennifer any thoughts?
Jennifer Charlebois
I would just add that there is always a variety of factors that, the way when you're looking at the toll lanes but one thing we have to look at is providing that type that gets the driver and adds some value to them. So that usually involves getting them past or through some sort of chokepoint for an interchange. And then looking at how as we mentioned how you can end the lane without creating extra disturbance.
Brian Kary
This is Brian from Minnesota. A similar response to trying to get to the choke point in trying to get to the actual destination for the majority of the drivers want to go through. And in terms of corridor length we have gotten turned in about 10 miles of 35W. So we are basically doing the 4 mile lane with the phase 1 and the extension study that comes to the north.
Jennifer Symoun
All right thank you. I think that we are about out of time. I think we got the most of the questions and I'll try to get the other ones out of the presenters so we can get some responses sent out to everybody. I do want to thank all of our presenters for presenting to thing giving great presentations. I would also like to thank everybody in attendance. The recording and the presentations will be posted online in the next few weeks and I will send out an e-mail when they are available. Without will go ahead and close out the day. Thanks to everybody and enjoy the last few weeks of the year.
