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Building upon the information gathered during the review of published literature, additional information regarding traffic monitoring in recreation lands at Federal, State, and local levels was gathered through a targeted survey of State and local agencies and the conduct of a recreational traffic monitoring workshop.
A targeted survey of ten State DOTs (Colorado, Florida, Idaho, Indiana, Missouri, Nevada, New Jersey, Utah, Wisconsin, and Wyoming) and three metropolitan planning organizations (Metropolitan Transportation Commission - San Francisco Bay Area, Metroplan Orlando, and Southwest Missouri Council of Governments) was conducted to identify current practices in collecting traffic data at and near recreational areas. Survey participants were selected based on the ability to provide geographic diversity, the likely presence of recreational travel, and the research team's familiarity with State and local agency staff.
Survey participants were asked to respond to a series of questions related to: their agency's conduct of continuous traffic counts; the number of ATRs and AVCs used for recreational and non-recreational traffic data collection; the nature and extent of any recreational, seasonal, or daily factor groups in use; and the nature and extent of roadway mileage under the agency's jurisdiction.
Key responses from the ten participating State DOTs are summarized in table 4. Nearly all of the participating State DOTs maintain one or more seasonal factor group for recreational traffic monitoring. Several States that have distinct winter and summer recreational traffic maintain two factor groups. The Florida DOT reported using more than two recreational traffic factor groups while the Indiana DOT reported using no factor group for recreational traffic.
Table 4. Recreational Factor Groups in Selected State Traffic Monitoring Programs
| State DOT | ATRs Statewide |
Recreational Factor Groups | ATRs per Recreational Factor Group |
|---|---|---|---|
| Colorado | 100 | Recreational: Ski Traffic | 14 |
| Special Case: Non-Ski Traffic, Casino Traffic | 25 | ||
| Florida | 274 | Many Different Recreational Factor Groups | NA |
| Idaho | 209 | Recreational Traffic | |
| Indiana | 103 | No Recreational Factor Groups | NA |
| Missouri | 95 | SFG004: All Recreational Traffic | 14 |
| Nevada | 93 | Recreational: Northern State Recreational-Tahoe | 3 |
| New Jersey | 65 | Recreational Traffic | 10 |
| Utah | 97 | Northern Recreational | 11 |
| Southern Recreational | 11 | ||
| Wisconsin | 150 | Urban Tourist Recreational | 5 |
| Rural Tourist Recreational | 35 | ||
| Wyoming | 162 | Recreational Traffic | 6 |
None of the planning agencies that were contacted indicated that they routinely monitor recreational traffic; instead, planning agencies rely upon their respective State DOTs to collect this data. Planning agencies may occasionally collect data in recreational areas to support planning uses, but this is done as part of a "special studies" process. Responses from the three metropolitan planning organizations are summarized below.
The Metropolitan Transportation Commission (MTC) is the transportation planning, coordinating, and financing agency for the nine-county San Francisco Bay Area. MTC staff analyze and report on State highway system traffic count data collected by the California State Department of Transportation. Technical summaries, available for years 1989 through 2007, include information on:
Persons interested in AADT counts or congestion and vehicle hours of delay estimates are directed to the California Department of Transportation databases.
No information was uncovered related to the distinct consideration of recreational traffic.
Metroplan Orlando is the MPO for Orange, Osceola, and Seminole Counties. The metropolitan area of Orlando has one of the fastest growing populations in the country, and, as a result, the number of new motor vehicles coming into the area is growing rapidly. Due to this growth, and the fact that the private automobile is the predominant mode of transportation, the area's highway system is becoming increasingly congested.
One of the main methods for measuring the level of activity on an area's highway system is the collection of traffic counts on major roadways. More than 300 traffic counts for various locations in Orange, Seminole, and Osceola Counties are obtained each year by the Metroplan Orlando staff from the Florida Department of Transportation (FDOT), the three counties, and from the City of Orlando. This information is published in a traffic count report that provides FDOT's daily (24-hour) bi- directional traffic counts averaged annually on major roadways.
No information was uncovered related to the distinct consideration of recreational traffic.
The Southwest Missouri Council of Governments (SMCOG) is a voluntary association of local governments in the ten-county area of southwest Missouri in the Springfield area. These include Barry, Christian, Dade, Dallas, Greene, Lawrence, Polk, Stone, Taney, and Webster counties. Branson is located in Taney County. SMCOG is administered and operated through the Center for Resource Planning and Management at Missouri State University. SMCOG is the only regional council in Missouri affiliated with a university. Through this unique partnership, SMCOG has access to a wide variety of resources and technical assistance at the university.
No information was uncovered related to traffic counts conducted by SMCOG or the distinct consideration of recreational traffic.
To supplement information gathered through the literature review and targeted survey, a recreational traffic monitoring workshop was conducted. The purpose of the workshop was to bring together State and Federal Land agencies to discuss current and preferred practices for monitoring traffic in recreational areas and to identify opportunities for improving traffic monitoring to and within Federal lands. A desired outcome of the workshop was sufficient information exchange leading to the development of guiding principles of traffic monitoring for recreational areas.
The workshop's agenda comprised presentations regarding traffic monitoring in recreational areas as performed by Federal, State, and Provincial agencies. Specific traffic monitoring practices that were described related to:
In addition, participants collectively identified broader challenges related to traffic monitoring in recreational areas.
Use of combined permanent and portable counters for data collection was generally reported; but differences in the quantity of count sites used (i.e., the number of units available), the subsequent geographic coverage, and the types of technologies (i.e., simplistic to advanced) were observed.
Regarding the use of technology in recreational areas, a number of field-related challenges were identified:
Representatives from the Wyoming DOT reported using satellite as alternative to cellular to overcome challenges related to communications coverage. Despite its perceived high cost, the use of satellite communications in Wyoming suggests that this technology is or is becoming a viable option where cellular coverage is unavailable or unreliable and where line-of- sight technologies are too costly or visually intrusive in sensitive areas.
Participants from NPS noted success in using:
Vehicle classification data is not routinely collected despite its noted value for decision- making. Cited limitations that currently prevent its collection include the following:
Weigh-in-motion (WIM) systems have been used to reduce misclassification errors associated with recreational vehicle types. However, the previously reported challenges related to the potentially high cost of permanently installed WIM systems and/or the low reported accuracies of less costly portable WIM systems limit this application.
On a related note, the representative from the Wyoming DOT presented a novel "virtual lane" equipment installation for distinguishing tandem motorcycle traffic from passenger car traffic. Each year in late July and early August, Wyoming DOT observes a significant spike in motorcycle traffic as motorcyclists travel through Wyoming on the way to the Annual Sturgis Motorcycle Rally in South Dakota. Motorcycles traveling in tandem are often erroneously classified as passenger cars using automated methods. This innovative practice was developed to more accurately explain and characterize traffic patterns during this time of year.
Short-duration counts are commonly conducted:
However, there were a few special practices for handling recreational traffic that were noted that did not conform to this pattern. The Nevada DOT conducts 7-day counts on an annual basis to account for their unique recreational traffic patterns related to casinos, and for consideration of weekend trips. No other participants reported conducting short duration counts on Friday, Saturday, Sunday, or Monday when recreational traffic may be more predominant. Instead, traditional traffic monitoring scheduling practices, better suited to reflect commuter traffic, are more often followed. The Washington State DOT conducts 48-hour counts twice per year in recreational areas to better capture seasonal variability. In Manitoba, Canada, 48-hour counts are also conducted twice per year, but this is not limited to only recreational areas.
When short-duration counts are scheduled, a portion of participants reported scheduling site counts:
Estimates of AADT may be seasonally adjusted using high volume average daily traffic (ADT) months. In Washington State, significant variation between different weeks in the same month necessitated the creation and use of week-specific instead of monthly factors.
Factor groups in use by participating agencies differed in both number and characteristics. Several of the participating agencies do not have defined "recreational" factor group(s). Factor groups are often assigned on the basis of:
Factor group assignment is generally supported by, in order of preference:
In Manitoba, Canada, traffic analysts use a factor group assignment algorithm that utilizes a series of questions that lend consistency to the decision-making process. While consistent questions are posed, this process does allow for some subjectivity in response.
For mixed-traffic facilities, consideration of traffic volumes on adverse weather days may distinguish recreational and "other" traffic. When the necessity of this information was questioned, participants indicated that there was value in determining the proportion of recreational traffic to support economic development considerations.
While traffic volumes are consistently captured, other traffic characteristics are less frequently captured despite their perceived value to enhance data quality and decision- making, such as:
As mentioned earlier, the capture of vehicle weight, in particular, is challenged by the potentially high cost of permanently installed WIM technology and/or the low reported accuracies of less costly portable WIM systems.
Among participating agencies, the motivation for collecting traffic data varied but generally included the following:
In general, Federal agencies tasked with managing recreational areas are primarily concerned with visitation and resource protection while State DOTs are more interested in roadway use and infrastructure preservation.
Ongoing development of and reliance upon management systems - particularly pavement/bridge, safety, and congestion management systems - will increase the importance for traffic data. The level of data detail required to support planning-level decisions and operations/maintenance-level decision differs. In addition, the sensitivity of decision-making outcomes to the nature and characteristics of input data varies by application and the level of sophistication of supporting computer models (e.g., some models provide less precise, qualitative outcomes and hence, require less precision from the input data).
Private industry also relies upon traffic data to support development/business decisions. Two examples provided by the NPS related to the production of Coleman™ camp stoves based on observed increasing or decreasing recreational travel trends and the site selection for new IMAX™ theatres that requires a minimum passing traffic volume (market) for development.
Data quality was reported to be dependent upon available costs and resources. Participating agencies reported the use of automated data validity checks prior to its use and distribution. The participant from the Utah DOT also noted that GIS programs provide convenient graphical displays for visually detecting problems with the data.
Missing data was generally reported directly as such by participating Federal land management agencies. State DOTs reportedly utilize formal procedures (AASHTO methods) for extrapolating data across missing time periods.
Data quality was thought to be often taken for granted. In a special study conducted to determine the adequacy of planned coverage counts and factoring processes for NPS lands, estimated AADT errors of nearly 50 percent were observed. For Forest lands, a pilot traffic data project, which attempted to factor sample counts using various surrogate information, concluded that reliability of traffic estimates cannot be determined without continuous traffic count (reference) data. This outcome not only suggests a high variability in recreational traffic but also raises questions as to the adequacy of "percent error" as a metric on highly variable and/or low volume roads. For lower volume roads, instead of characterizing data quality solely in terms of percent error, perhaps a combination of percent and absolute error could be reported. One participant reported that the Ohio DOT reports absolute error when traffic volumes are below a specified threshold and percent error when traffic volumes exceed the same threshold. For recreational roads with considerable and varying levels of traffic and/or peak surge periods, it may be most appropriate to set a realistic data value target that meets specific requirements of the users instead of attempting to comply with an unrealistic standard precision requirement common to other roads.
None of the workshop participants provided a clear indication of data quality requirements, either in general or for specific data applications. As such, few workshop participants reported having a clear and comprehensive understanding of their existing data quality (i.e., without defined data quality requirements, scarce resources will be directed to activities other than determining data quality). A systems engineering approach was recommended to define data needs, verify that the requirements are met, and validate that the requirements are appropriate.
An underlying challenge to this effort is that quality improvements may not be viewed as necessary by all participating agencies. While general consensus indicated that data shortcomings currently exist, improving traffic data extent or quality may not be a priority and/or may not be supported by existing resources.
Over time, the reporting of traffic data has migrated from published annual (or more frequent) reports to CDs, DVDs, and most recently, the Internet, providing timely on- line access to data. The level of reporting detail and frequency was observed to vary among participating agencies. A number of participating agencies reported including caveats regarding data quality to limit the potential for liability.
Data sharing is variable but generally limited among participating agencies. Some examples of successful data sharing partnerships include the following:
Opportunities to include FLMAs in the existing FHWA Traffic Management System (TMS) traffic data repository were discussed and appear promising. The FHWA Office of Highway Policy Information also offered to make the HPMS traffic data currently reported by States available to participating agencies through the FHWA Federal Lands Highway Division to support related decision-making.
At the State level, participants from the Colorado DOT described their successes in developing a comprehensive integrated database using multiple traffic count data sources, noting a 35 percent increase in traffic count data available to the Colorado DOT valued at $87,000. The Colorado DOT also noted that the development of such a database requires the use of common terminology and a common attribute of interest (e.g., traffic volumes) among all contributors. A common traffic monitoring database such as this must also recognize and account for different quality levels when various data sources are being integrated/ combined.
A number of broader, overarching challenges to traffic monitoring in recreational areas were identified. These include the following:
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An introductory webinar to assist local and tribal agencies with applying for transportation funding under the Bipartisan Infrastructure Law (BIL).
