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Publication Number: FHWA-RD-01-15
Date: March 2002
Study of Adequacy of Commercial Truck Parking Facilities
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6.0 SUMMARY AND CONCLUSIONS
Section 4027 of the TEA-21 requires:
…a study to determine the location and quantity of parking facilities at commercial truck stops and travel plazas and public rest areas that could be used by motor carriers to comply with Federal hours of service rules. The study shall include an inventory of current facilities serving the National Highway System, analyze where shortages exist or are projected to exist, and propose a plan to reduce the shortages.
This report, which has been prepared in cooperation with research entities representing motor carriers, the travel plaza industry, and commercial motor vehicle drivers, presents the findings of the Section 4027 study. These findings include results of a national driver survey, estimates of truck parking demand generated by a demand model, estimates of truck parking supply generated by a national inventory of truck parking facilities, and comments and recommendations on the issue of truck parking from State partnerships and national stakeholders. Sections 2.0 through 5.0 of this report describe the detailed results of this study, which are summarized in the list below:
Although there is a consensus that the adequacy of truck parking is an important issue that must be addressed, there is wide disagreement both among the various stakeholder groups and among the States about the best approach to addressing the problem. Although the problem has national consequences, both the problem and the proposed solutions seem to be more local in nature. For example, some States have an apparent shortage of parking spaces while nearby States have an apparent surplus, and any shortages that do exist are often concentrated on a few sections of highway within a State. The solutions, too, can be local in nature, with some States proposing to leverage existing ITS initiatives to broadcast parking information, others proposing to open more parking facilities, and others relying on private industry to meet the demand. One point of agreement, however, is that the various agencies, organizations, and special interest groups worked together as part of the State partnerships and want to continue to work together to address this issue.
The previous sections of this report provide detailed information about the adequacy of truck parking on the NHS. These results, when presented and viewed as a series of snapshots, tell only part of the story. Missing from that type of snapshot presentation is the bigger picture that surrounds the adequacy of commercial truck parking facilities serving the NHS. To wit: Is there a truck parking problem, and if so, what should be done about it? This section looks at the bigger picture by posing a series of questions whose answers are key to understanding and addressing the adequacy of truck parking and suggesting answers to these questions that are synthesized from the report findings. In particular, nearly all of the suggestions identified below are restatements of recommendations made by the State partners for the express purpose of establishing a starting framework for considering solutions to specific truck parking problems.
An inadequate supply of truck parking spaces can result in two negative consequences: (1) tired truck drivers may continue to drive because they have difficulty finding a place to park for rest, and (2) truck drivers may choose to park at unsafe locations, such as the shoulder of the road and exit ramps, if they are unable to find available parking. Both of these consequences generate a safety hazard for the truck driver and for other drivers using the NHS. However, any program meant to address the problems of an inadequate supply of truck parking spaces must concentrate on a number of issues beyond simply providing additional parking spaces. For example, a Federal program that simply earmarks funds for each State to build new truck parking may not completely address the “big picture” need. Earmarking funds for every State may not be necessary if some States already have a sufficient supply of truck parking. Also, building spaces that have neither the convenience nor the amenities necessary to convince a truck driver to use the spaces would not help; tired truck drivers would either continue to drive to locate spaces with preferred amenities or would park in unsafe locations because of the greater convenience. Finally, parking spaces need to be adequately spaced so that a surplus of spaces is not developed in a select group of locations while other roadway segments continue to have an inadequate supply of spaces. Consequently, the analyses and conclusions in this report will regularly refer back to these issues.
In determining whether the supply of truck parking spaces is adequate, it is important to evaluate not only the total supply of truck parking, but also the distribution (i.e., Are spaces located at the places necessary to meet demand?) and type (i.e., Will truckers use the spaces?) of those parking spaces.
A key issue is to determine what types of parking spaces are available. That is, do the available spaces have the convenience and amenities necessary so that the driver will choose to use them? If these spaces do not meet the needs of a driver, the driver may choose to either drive tired or park on the shoulder. This fact leads to another key element in addressing this problem: a proposed solution must not only consider the number of available spaces, but must also consider the factors that influence truck drivers’ choices about where and when to park.
A second key issue is to determine whether the distribution and spacing of parking spaces address the factors that impact the need for these spaces. For example, an important factor impacting the demand for truck parking spaces is the HOS regulations, which place strict limits on the number of consecutive hours a truck driver may drive. If a driver has “used up” his hours, she/he is forced to either violate these regulations or find a place to rest. If there are no legal parking spaces available, the driver must either park at an unsanctioned location (e.g., an exit ramp) or continue to drive until a parking space is located. Similarly, a very tired driver must either find a parking space immediately or continue to drive while tired. This leads to the following observations about the truck parking problem with respect to distribution and spacing:
The driver surveys, field observations, and demand model calculations all support the conclusion that there is a shortage of truck parking spaces at many locations in the United States and that this shortage is worse for parking at public rest areas than at commercial truck stops and travel plazas. Shortages also appear to be worse for non-Interstate highways, though the fact that those highways are often not access-controlled makes it more likely that other types of parking spaces (i.e., not at public rest areas or commercial truck stops or travel plazas) are used as supplemental parking.
The demand model provides a useful method for identifying locations at which parking shortages may exist, but further investigation is required to confirm the implications of the demand model. For example, the demand model does not consider the fact that demand generated in one section of a highway can often be safely met by supply in a nearby section or that a driver who is getting tired might stop early to park at a favored facility. Also, the demand model does not consider a number of local factors that can influence demand, such as a higher rate of parking near major distribution centers. Further research and refinement of the demand model could help sharpen the demand estimates made with the model. In the meantime, it should be used as only an indicator of potential shortages.
Finally, there is the question of the type of parking (public or private) that is available. Many field surveys have observed that drivers choose to park at overcrowded public rest areas or on the shoulder when parking is available at a nearby commercial truck stop or travel plaza. This could be caused by the uncertainty of finding parking at a nearby truck stop, the relative difficulty of entering and exiting a truck stop, or some other reason. If steps are taken to reduce the factors that make some truck drivers favor parking at public rest areas (or even on shoulders), then the commercial truck stop industry can be effective in addressing the need for truck parking. However, as long as truck drivers view these types of parking spaces differently, a need will exist for both types of parking spaces.
6.2.3 Is it appropriate for the State and Federal governments to take steps to address any inadequacies in truck parking, if they exist?
Even if there is a shortage of truck parking spaces, it may not be the responsibility of the State or Federal government to address the problem. Certain stakeholder groups have argued that expanding public parking for commercial vehicles amounts to a subsidy of the trucking industry and unfairly penalizes the commercial truck stops that serve it. Parallels have been drawn to the aviation industry, where Federal HOS regulations limit pilot flying time, but the Federal government does not help provide sleeping facilities for the pilots.
The other side of the issue is that tired truck drivers pose an imminent health risk to other drivers on the road and that governments have a prevailing interest to protect citizen-drivers by helping tired truck drivers find rest. This view is supported by the existence of citizen-led organizations that are lobbying the government to address this problem and by the media attention that this problem has drawn.
The clearest indication of whether the government has a role to play in addressing this issue comes directly from the comments of the stakeholders interviewed for this study. While different stakeholders prefer different roles for government, ranging from leveraging ITS technologies to better disseminate information about available parking spaces to building more and better public parking facilities, most stakeholders do agree that government should play a role. For example, a large number of State partner groups advocate a hybrid approach that involves the commercial industry working with the State and/or Federal government to help solve the parking problem.
The first step in alleviating parking shortages is to identify the locations at which those parking shortages exist. The demand model and supply inventory represent a good first step in achieving this goal. The primary limitations of this model, however, are that it does not consider a number of local factors that can affect local demand (e.g., proximity to distribution centers that results in truck drivers staging at parking facilities, proximity to other parking facilities that absorb demand, and consideration of travel patterns that affect the short-haul/long-haul ratio). Because of these limitations, the model should be used as a guideline for identifying possible locations of parking shortages that can be evaluated more carefully through additional study and field observations.
As a first step in this process, State governments can use their knowledge of local conditions to refine the model for local usage. For example, the model may estimate that the parking supply for an important North-South travel corridor is “at capacity.” Because the route of interest is an important long-distance travel corridor, however, the proportion of long-haul vehicles on the route is likely higher than that used in the model, which will result in a greater demand than that estimated by the model. Alternately, a route between two nearby population centers may generate an unusually high amount of short-haul commercial traffic, which will result in a smaller demand than that estimated by the model. In each case, model parameters can be calibrated specifically for these routes in order to generate more accurate demand estimates.
Once locations with possible shortages have been identified, field observations can be used to verify the shortage prior to implementation of any expensive plans to address the perceived shortage. These field observations should note not only signs of over-utilized parking facilities (e.g., parking above capacity at public rest areas and parking on shoulders), but also under-utilized parking facilities that may be nearby. Many field studies have already identified situations in which public rest areas were full and overflowing and trucks were parking on shoulders and exit ramps, but capacity still existed at nearby commercial truck stops and travel plazas. To identify the most cost-effective solution to a local truck parking problem, the field observations must identify existing resources that might be used to address the problem. Useful resources might include under-utilized parking at commercial truck stops and travel plazas; VMSs, radio broadcasts, and Intelligent Transportation Technology (e.g., Global Positioning System) to deliver real-time parking information and other public facilities on the highway (e.g., park-and-ride lots and weigh stations) that could be opened for parking at night. Several State partners have recommended that the Federal government facilitate this process by providing funds to conduct additional studies (e.g., field observations) where parking shortages are suspected. Furthermore, implementation guides can be developed to help standardize and increase the effectiveness of these studies, as can evaluation guides to help interpret the results of these studies for the purpose of formulating cost-effective plans for addressing the problem.
One of the most powerful features of the truck parking demand model is its ability to estimate future demand so that long-range plans can be formulated to accommodate this future demand. States could use this model to initially identify locations with possible parking shortages, then, based on local knowledge and field observations, refine the model to better reflect local conditions. The refined model could then be used to make long-term projections of parking demand so that appropriate long-term plans could be implemented.
When a parking shortage has been identified, a number of alternatives exist for how best to address that shortage. The alternatives that are best for a particular location will depend primarily on the local observations that were made while verifying the parking shortage. The following list describes some local observations that may be made and the possible solutions. The suggestions listed below are restatements of various suggestions made by the State partners consulted as part of the research for this report:
This report has presented a discussion of the model’s limitations and how the limitations hinder the ability of the model to accurately estimate demand at the segment level. While the demand model used in this study provides reasonable estimates of truck parking demand, improvements could be made to the model in the future to improve its ability to estimate parking at a more microscopic level. One specific limitation is that the model estimates demand for highway segments, ignoring variations in the parking supply that affect where drivers can park. Thus, there is currently a factor missing from the model that represents the geographic distribution of supply. Therefore, when field counts are compared to model estimates, as was done during calibration, it is not surprising that, in some cases, the estimates for one segment are too low, while the estimates for the next segment are too high. Additional research into how to add a factor to the model that represents the distribution of parking supply would make the model more accurate at the segment level and more useful for local planning purposes.
The model estimates parking demand as a result of truck drivers’ needs to rest and obtain services. It does not consider other factors that might influence demand in a particular region, such as typical commodity flows or the desire to “stage” close to a shipper/receiver for more quick and easy access. In contrast, the model distributes demand evenly across the network without consideration of these types of factors. Research into commodity flow patterns (particularly where flows are heavy) and the location of large distribution centers, ports, etc., could provide insight into “loading” factors that could be used in the model to help distribute the demand in a more realistic fashion. Additional research into commodity flow patterns is especially important because just-in-time delivery is becoming the standard for the movement of goods and products in the United States.
The report discussed the short-haul to long-haul ratio, factors that might affect its variability, and how the variability was modeled (by classifying each highway segment as either rural or urban and using a different value for the ratio for rural and urban segments). This methodology, however, may not capture the true variation in this parameter, and a more realistic model for estimating this ratio for each highway segment would likely result in better demand estimates. Therefore, it is recommended that future research be performed to understand how, when, and where the short-haul to long-haul ratio varies and what factors affect its variance. This could be accomplished by conducting origin-destination studies at a variety of geographic locations and at different times of the day.
As discussed in the report, the model was calibrated using data collected along nine corridors in four regions. The demand estimates from the calibrated model were examined for face validity by analysts and State partnerships; however, no formal validation process was performed. It is recommended that more field observational studies be conducted and that the results of these studies be used for model validation.
A number of States recommended the development of public-private partnerships to assist with the development and financing of additional parking spaces. However, public-private partnerships often represent new ground for States, as these partnerships may involve pooling funding, sharing risk, and accommodating the need for the private sector to show profit on investments. These types of funding and risk-sharing arrangements often are at variance with more conventional State procurement practices and can be difficult for States to implement. Candidate issues associated with the creation of public-private partnerships for providing additional truck parking spaces include the following:
The study team believes that moving this particular recommendation forward will require additional research that documents how a successful public-private partnership that implemented a similar type of project succeeded. [d] This research would include such issues as the following:
The expected outcome of this research would be a case-study document that States would be able to use as a reference document to guide the development of other public-private partnerships.
A common complaint heard throughout the course of the study was that drivers have a difficult time obtaining information on the location and whereabouts of facilities with available parking. This complaint was mirrored by similar complaints from commercial truck stop and travel plaza operators that they often have available spaces while drivers are parking on exit ramps and road shoulders. In the driver interviews, drivers indicated that they prefer not to park in overcrowded lots where driving can be difficult. A number of States recommended that providing information to drivers on the location of available parking facilities would help address these issues and help drivers find a place to obtain adequate rest.
Many States are studying how this type of information can be made available to drivers. Maryland, for example, received a grant from the I-95 Corridor Coalition to study the feasibility of using VMSs to provide information to truckers on the location of available truck parking.
Additional research in this area might include the following:
The expected product of this research would be a “lessons learned” report documenting issues that States would need to consider in developing and implementing such a service.
[a] The NTSB identified 19 States that have laws limiting the amount of time that a vehicle can park at a public rest area, 16 of which were also identified in this study. Three of the States identified by the NTSB did not provide complete information to this study team on whether there were time limits for some rest areas within the State.
[b]The truck parking supply inventory described in section 3.0 estimated both a minimum and a maximum supply for each highway segment. For the purpose of determining the demand/supply ratio, the maximum value was used. This approach helped ensure that the demand/supply ratio provided a conservative estimate of the locations at which inadequate truck parking exists.
[c] The 18 States cited refers to those States that identified this strategy in their draft action plans. It does not necessarily reflect the total number of States in which individual truck stop operators plan to expand facilities.
[d]An excellent summary of the types of issues encountered in developing public-private partnerships and recommendations on how to address these is presented in the ITS America/DOT-sponsored study Choosing the Route to Traveler Information Systems: Decisions for Creating Public/Private Business Plans. Although this report focuses primarily on Advanced Traveler Information Systems (ATIS), many of the issues will be similar to creating public-private partnerships for providing additional truck parking spaces.
Topics: research, safety, freight/goods movement
Keywords: research, safety, commercial motor vehicles, truck stop, rest area, travel plaza, truck parking, TEA-21 Section 4027 study, human factors, parking studies, parking supply, truck driver survey, parking demand model
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