Skip to contentUnited States Department of Transportation - Federal Highway Administration FHWA Home
Research Home
Report
This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-RD-01-158
Date: March 2002

Study of Adequacy of Commercial Truck Parking Facilities

PDF Version (7.25 MB)

PDF files can be viewed with the Acrobat® Reader®

4.0 COMMERCIAL TRUCK PARKING SUPPLY/DEMAND BALANCES

4.1 Methodology

The methodology used to analyze where shortages exist or are expected to exist involved a six-step process. First, the supply of available truck parking spaces was inventoried based on a database of commercial truck stops and travel plazas and a survey of public agency rest areas. Second, a parking demand model was developed and calibrated (based on a limited data set) to estimate parking demand along highway segments.Third, demand estimates from the preliminary model were sent to States and State partners for review and comment.Fourth, the model estimates were refined, based on the partnerships’ comments, and the model was re-calibrated based on additional field data. Fifth, the new estimates were sent back to the partners for a final round of review and comment. Sixth, model estimates were refined based on the partners’ comments, and the results of the analyses were used in this report.

Note that the results of these analyses were meant to assist in developing strategies and plans to reduce or better manage any shortages. The information was not intended to provide a sufficient level of detail to define the specific location and quantity of truck parking spaces required. The design-level detail required to complete this type of needs assessment was not practical within the time frame and resources of this study. However, the supply and demand information provided at the corridor level did fulfill the goal of identifying system-level problems and needs that can serve as the bases for the formulation of policy alternatives and the conducting of a more detailed study at a later time. In fact, many of the partners used the supply and demand results described above for exactly this purpose.

4.2 Determining Current Level of Parking Space Utilization

The analysis conducted for this study included information compiled for 49 States and addressed all the Interstate highways as well as a significant share of non-Interstate highways that comprise the NHS. Detailed modeling analysis and truck parking space inventory were conducted for nearly 520 individual roadway segments. By comparing the estimated demand with the inventoried supply, it was possible to determine if a shortage of truck parking existed along a highway segment.

To simplify the interpretation, a rating system was developed to summarize the results of the supply and demand analysis. Dividing the estimated demand by the estimated supply for both public and private parking spaces formed a demand/supply ratio that indicated the level of utilization statewide.[b] A ratio less than one indicates that demand is smaller than supply and an apparent surplus of spaces exists, while a ratio greater than one indicates that demand outstrips supply and there is an apparent shortage.

Because of the uncertainty of the demand and supply estimates, using one as an exact cutoff for indicating whether shortages exist is not appropriate. Instead, the demand/supply ratios have been grouped into three categories, as indicated in table 15 .The first category, “Surplus Spaces,” indicates that the number of parking spaces available is likely to exceed the peak demand. The second category, “Sufficient Spaces,” indicates that the peak demand and the supply of parking spaces are nearly the same. The third category, “Shortage of Spaces,” indicates that overcrowding is likely. Because the estimates of truck parking supply indicate a range of parking spaces, several different supply values could be used in determining this ratio; the results in this report use the maximum estimated truck parking spaces.

Table 15. Demand/supply ratio categories.

Demand/Supply Ratio
Parking Space Utilization
Less than 0.9
Surplus Spaces
0.9 to 1.1
Sufficient Spaces
More than 1.1>
Shortage of Spaces

Table 16 contains a national summary of the results using the parking space utilization classification method. These results provide a general sense of the level of unmet needs for commercial truck parking. A total of 35 States are rated as having a shortage of spaces at public rest areas, while a total of 8 States are rated as having shortages at commercial truck stops and travel plazas. When looking at a combined rating (i.e., the sum of demand and supply for both public rest areas and commercial truck stops and travel plazas), a total of 12 States are rated as having shortages.

Table 16. Parking space utilization: National summary of demand/supply ratio along interstates and other NHS routes carrying more than 1,000 trucks per day.

Parking Space Utilization
Public Rest Areas
Commercial Truck Stops1
Total
Shortage of Spaces
35
8
12
Sufficient Spaces
4
6
8
Surplus Spaces
10
34
29

1This column excludes Alaska, which did not report on the number of parking spaces available at commercial truck stops and travel plazas.


Table 17 provides a State-by-State breakdown of these results. The “Ratio” column lists the demand/supply ratio, and the “Category” column lists the parking space utilization category for each State. The “Public” column refers to the demand/supply ratio for parking spaces at public rest areas, the “Commercial” column refers to the demand/supply ratio for parking spaces at commercial truck stops and travel plazas, and the “Total” column refers to the ratio for parking spaces at both types of facilities.

In addition to determining where truck parking shortages currently exist along the NHS, the study also attempted to estimate where future shortages might exist. Table 7 lists the expected annual growth rate for the truck parking space demand for each of the 49 States considered in this study, with values ranging from 0.5 to 4.4 percent. In section 3.0 , the expected annual growth rate for the supply of truck parking spaces is estimated at about 1 percent for public spaces and about 6.5 percent for commercial spaces. Because the estimated growth rates for parking supply are national averages and local growth will vary considerably, it is not appropriate to use these figures to generate State-specific estimates of the future adequacy of truck parking space supply. However, the following observations can be made:

  • The expected growth in supply of public spaces is not projected to match the expected growth in demand. As there is already an apparent shortage of public spaces in many States, this projection indicates that the shortage of public spaces will worsen in the future unless steps are taken to either 1) increase the growth rate of public spaces or 2) increase the interchangeability between public and commercial spaces so that the relative demand for public spaces decreases.
  • The expected growth in supply of commercial spaces is projected to exceed the expected growth in demand, indicating that the surplus of commercial spaces is likely to increase in the future.

Table 17. Parking space utilization: Demand/supply ratio along interstates and other NHS routes carrying more than 1,000 trucks per day.

 
Public
Commercial
Total
State
Ratio
Category
Ratio
Category
Ratio
Category
Alabama
2.29
Shortage
0.79
Surplus
0.93
Sufficient
Alaska1
0.05
Surplus
N/A
N/A
N/A
Surplus
Arizona
1.88
Shortage
0.43
Surplus
0.53
Surplus
Arkansas
5.20
Shortage
0.79
Surplus
0.99
Sufficient
California
4.10
Shortage
2.03
Shortage
2.29
Shortage
Colorado
4.55
Shortage
0.94
Sufficient
1.15
Shortage
Connecticut
1.71
Shortage
1.66
Shortage
1.67
Shortage
Delaware
2.94
Shortage
2.14
Shortage
2.28
Shortage
Florida
0.99
Sufficient
0.77
Surplus
0.81
Surplus
Georgia
1.88
Shortage
0.64
Surplus
0.75
Surplus
Idaho
3.00
Shortage
1.25
Shortage
1.44
Shortage
Illinois
2.63
Shortage
1.16
Shortage
1.33
Shortage
Indiana
1.77
Shortage
0.99
Sufficient
1.10
Shortage
Iowa
0.86
Surplus
0.44
Surplus
0.50
Surplus
Kansas
1.24
Shortage
0.44
Surplus
0.51
Surplus
Kentucky
2.23
Shortage
1.03
Sufficient
1.17
Shortage
Louisiana
9.32
Shortage
0.75
Surplus
0.96
Sufficient
Maine
1.81
Shortage
0.55
Surplus
0.66
Surplus
Maryland
2.01
Shortage
0.87
Surplus
1.00
Sufficient
Massachusetts
6.16
Shortage
1.51
Shortage
1.83
Shortage
Michigan
0.81
Surplus
0.69
Surplus
0.72
Surplus
Minnesota
1.63
Shortage
0.65
Surplus
0.75
Surplus
Mississippi
2.93
Shortage
0.60
Surplus
0.73
Surplus
Missouri
4.28
Shortage
0.72
Surplus
0.89
Surplus
Montana
1.18
Shortage
0.50
Surplus
0.58
Surplus
Nebraska
0.95
Sufficient
0.30
Surplus
0.35
Surplus
Nevada
2.62
Shortage
0.46
Surplus
0.57
Surplus
New Hampshire
0.84
Surplus
0.35
Surplus
0.40
Surplus
New Jersey
0.69
Surplus
0.41
Surplus
0.45
Surplus
New Mexico
15.62
Shortage
0.65
Surplus
0.83
Surplus
New York
1.43
Shortage
0.87
Surplus
0.95
Sufficient
North Carolina
1.98
Shortage
0.58
Surplus
0.69
Surplus
North Dakota
0.72
Surplus
0.31
Surplus
0.36
Surplus
Ohio
2.35
Shortage
0.96
Sufficient
1.12
Shortage
Oklahoma
1.41
Shortage
0.37
Surplus
0.45
Surplus
Oregon
1.89
Shortage
0.67
Surplus
0.79
Surplus
Pennsylvania
1.82
Shortage
0.54
Surplus
0.65
Surplus
Rhode Island
0.63
Surplus
1.35
Shortage
1.07
Sufficient
South Carolina
1.55
Shortage
0.50
Surplus
0.59
Surplus
South Dakota
0.54
Surplus
0.50
Surplus
0.51
Surplus
Tennessee
1.58
Shortage
0.63
Surplus
0.74
Surplus
Texas
12.70
Shortage
1.18
Shortage
1.49
Shortage
Utah
1.64
Shortage
0.53
Surplus
0.62
Surplus
Vermont
0.15
Surplus
0.20
Surplus
0.19
Surplus
Virginia
2.16
Shortage
0.80
Surplus
0.93
Sufficient
Washington
1.79
Shortage
1.02
Sufficient
1.14
Shortage
West Virginia
0.92
Sufficient
0.92
Sufficient
0.92
Sufficient
Wisconsin
0.97
Sufficient
0.35
Surplus
0.41
Surplus
Wyoming
0.56
Surplus
0.39
Surplus
0.42
Surplus

1Alaska did not report the number of commercial parking spaces; however, the number of public spaces exceeded the estimated total demand.

4.3 Results from the Driver Survey

Several hundred drivers provided written and verbal comments, both solicited and unsolicited, regarding the availability of truck parking. Overwhelmingly, drivers remarked that there are not enough parking spaces at either public rest areas or commercial truck stops and travel plazas, particularly during the overnight hours. Drivers also reported that more parking is needed near metropolitan areas and in certain regions of the country (e.g., Northeast, Southern California, Northwest).

Drivers were asked how frequently they encounter available parking at public and commercial truck parking facilities (table 18). Among the overall sample, only 11 percent of respondents indicated that they frequently or almost always find available parking at public rest areas and only 34 percent of respondents reported that they frequently or almost always find available parking at commercial truck stops. Forty-eight percent of respondents indicated that they only rarely or almost never find available parking at public rest areas, while only 16 percent reported that they only rarely or almost never find available parking at commercial truck stops.

Table 18. Frequency with which drivers find available parking at public rest areas and commercial truck stops.

Type of Facility
Almost Never
Rarely
Sometimes
Frequently
Almost Always
Public Rest Areas
14%
34%
41%
9%
2%
Commercial Truck Stops
4%
12%
51%
25%
9%

Drivers also had the opportunity to rate how often their next stop (e.g., shipper or receiver) has available parking. The most frequently reported response (by 40 percent of the sample) was that sometimes their next stop has available parking. Thirty-seven percent of drivers reported that their next stop has available parking rarely or almost never. Twenty-three percent indicated that their next stop has available parking frequently or almost always.

Previous | Table of Contents | Next

ResearchFHWA
FHWA
United States Department of Transportation - Federal Highway Administration