Status of the Nation's Highways, Bridges, and Transit:
2002 Conditions and Performance Report
|Chapter 3: System Conditions|
Part I: Description of Current System
Part II: Investment Performance Analyses
Part III: Bridges
Part IV: Special Topics
Part V: Supplemental Analyses of System Components
U.S. transit system conditions can be analyzed by examining the aggregate number and type of transit vehicles in service, their average and condition, the physical condition and age of bus and rail maintenance facilities, and the condition of transit rail infrastructure components such as track, power systems, stations, and structures.
The National Transit Database (NTD) collects information from urban transit operators on fleet size, age distribution of vehicles, vehicle maintenance expenditures, and vehicle utilization, i.e., revenue miles traveled. The NTD data, however, does not provide information on the overall condition of vehicles. The Federal Transit Administration (FTA) has found the condition of vehicles of the same age can vary considerably, depending on factors such as the quality of vehicle maintenance and the geographic location in which the vehicles operate. Vehicles that are well maintained will generally be in better condition for their age than vehicles that are not. Vehicles that operate in coastal areas or in areas where salt is extensively used to melt ice during the winter also deteriorate more rapidly than vehicles that do not operate under those conditions.
FTA conducted extensive studies to estimate the mathematical relationship between the condition of a transit asset—a vehicle, facility, or rail track—and the age of the asset, its usage rate, and, when available, its maintenance history. Initial estimations of these relationships were based on extensive data collected by the Regional Transportation Authority of Northeastern Illinois and the Chicago Transit Authority in the 1990s and mid-1980s. This information was used to estimate the relationship between asset condition, age, and maintenance history over a ten-year period. The results of this study are available in a January 1996 FTA report, The Estimation of Transit Asset Condition Ratings.
Improvements to this estimation process have been and continue to be developed. As part of this effort, FTA has undertaken additional engineering surveys. In 1999, engineering assessments were made of the physical conditions of 77 bus maintenance facilities and 572 buses belonging to 31 transit operators. In 1999 and 2000, the physical conditions of 120 rail vehicles at ten different transit operators were also rated, with an emphasis on heavy rail vehicles and facilities. A subsequent survey of rail vehicles and facilities was undertaken in 2001, with inspections of the conditions of 36 rail facilities and 72 rail vehicles of 12 transit operators. This 2001 survey was split fairly evenly between heavy and light rail facilities and vehicles. The data collected by these studies have been used to refine the mathematical relationship used to estimate conditions for buses, heavy and light rail vehicles, facilities, and stations and to update the condition information that is presented in this chapter. No surveys of commuter rail vehicles or facilities were undertaken as a part of this effort. Commuter vehicles and facilities will be surveyed for the next version of this report.
Each vehicle and maintenance facility that was examined in an engineering assessment is assigned an overall level of condition based on a weighted average of the condition level assigned to the subcomponents of each vehicle and maintenance facility. For example, light rail vehicle subcomponents examined include the couplers, frame, bolster, gearbox, pneumatic piping, and the wiring and connections. Vehicles’ exterior and interior subcomponents are also rated. Maintenance facility components that are evaluated include the roof structure, heating and ventilation systems, mechanical and plumbing systems, electrical equipment, specialty shops, and work bays. Subcomponents examined include—in the case of the roof structure—the exterior roofing frame, gutters and drainage system, and interior roof frame. In the case of specialty shops, the condition of each type of shop (e.g., machine shop, metal working shop) is evaluated separately. Condition ratings of bus vehicles and bus maintenance facilities are undertaken in a similar fashion.
The physical condition of each asset is rated on a scale of 1 to 5 with 5 being the highest level of condition. This scale corresponds to the Present Serviceability Rating (PSR) formerly used by the Federal Highway Administration (FHWA) to evaluate pavement conditions. A rating level of 5, or excellent, is synonymous with no visible defects, or nearly new condition. At the other end of the scale, a rating level of 1 indicates that the asset is in need of immediate repair and may have a seriously damaged component or components [See Exhibit 3-37].
Bus Vehicle Conditions
The 1999 C & P Report revised bus vehicle conditions downwards based on survey information on the physical condition and age of bus vehicles collected by the National Bus Condition Assessment. This survey revealed that, on average, the condition of bus vehicles declined much more rapidly in the first five years of operation than was previously believed (from condition level 5 to about 3.25), after which the rate of decline was found to slow substantially with a condition level of 2.5 being reached after about 15 years, and 2.0 after 20 years.
Bus vehicle condition and age information is reported according to bus vehicle type for 1987-2000 in Exhibit 3-38. In 2000, the estimated average condition of the urban bus fleet was 3.07, up from 2.96 in 1997. Average bus vehicle age was reported to be 6.8 years, up slightly from an average age of 6.6 years in 1997. Since 1987, larger vehicles (articulated, full-size and mid-size buses) have tended to have, on average, slightly lower-rated conditions than smaller vehicles (small buses, vans). Full size buses have consistently been operating at just below the adequate condition level.
Articulated buses have exhibited the most significant changes in condition levels, falling from a condition of 3.08 in 1987 to 2.49 in 1997, increasing to 3.33 in 2000. This fluctuation is most likely the result of a 12- year industry replacement policy and the fact that the bulk of articulated buses were purchased in 1983-84. This replacement cycle is also evidenced by a peak in the percentage of overage articulated buses at 61 percent in 1997, and subsequent decline to 29 percent in 2000. In all years, mid-sized buses have maintained an average condition above 3.0 and both small buses and vans have consistently maintained an average condition of more than 3.5.
Urban Bus Maintenance Facilities
The estimated age distribution of urban bus maintenance facilities in 2000 is shown in Exhibit 3-39. This distribution is based on age information collected by the 1999 National Bus Condition Assessment, and applied to the 2000 national bus facility total as reported in the National Transit Database. Ninety-two percent of bus maintenance facilities are estimated to be more than 10 years old and 31 percent are more than 30 years old. Individual facility ages may not relate well to condition, since substantive renovations are made to facilities at varying intervals over time.
In 2000, the condition of bus maintenance facilities was estimated to be 3.23. Exhibit 3-40 provides the estimated condition level distribution of bus maintenance facilities. In 2000, 54 percent of all urban bus maintenance facilities were in adequate condition, 8 percent in good condition, and 9 percent in excellent condition, for a combined total of 71 percent in adequate-or-better condition (declining from 77 percent in 1997). Twenty-nine percent, however, are estimated to be in unacceptable condition—24 percent in substandard condition, and 5 percent in poor condition.
Rail Vehicle Conditions
The average condition of all rail vehicles except commuter rail has been re-estimated, based on engineering surveys of rail vehicle physical conditions undertaken between 1999-2001, following the completion of the 1999 C & P. The revision in rail vehicle conditions is similar to the one that occurred for bus vehicles in the 1999 Report. Analysis of the rail condition information collected in the survey revealed that rail decay curves follow a similar pattern as those for buses, i.e., rail vehicles decline rapidly during their first 5 years and more slowly thereafter. The conditions for commuter rail vehicles, for which the condition estimation procedures have not been reexamined, remain higher than for other rail vehicles. The conditions level for commuter rail vehicles reported here differs slightly from those in the 1999 C&P Report, based on the application of more comprehensive vehicle information.
In 2000, all rail vehicles were estimated to have an average condition of 3.55, down marginally from an average condition level of 3.71 in 1997. Condition levels in the 1999 Report for heavy and light rail vehicles have been revised downward by approximately one full point, from levels ranging from 4.0 to 4.7 to levels ranging from 3.25 to 3.64. Rail condition estimates are provided in Exhibit 3-41.
Rail vehicles have been, on average, in slightly better condition than bus vehicles between 1987 and 2000, with average condition levels consistently remaining above 3.5. Weighted-average rail vehicle age increased from 15.6 years in 1987, to 20.4 in 1997, to 21.8 years in 2000. The decline in average condition and increase in age has been driven by commuter rail self-propelled passenger coaches and heavy rail vehicles. The condition of commuter rail self-propelled passenger coaches has steadily declined from a condition of 5.0 in 1987 to 4.07 in 2000; the condition of heavy rail vehicles declined more gradually, from 3.59 in 1987 to 3.25 in 2000; the percentage of overage commuter rail self-propelled passenger coaches and heavy rail vehicles has also increased—for commuter rail self-propelled passenger coaches from 2 percent in 1987 to 61 percent in 2000, and for heavy rail vehicles from 15 percent in 1987 to 40 percent in 2000.
Conditions and ages for other rail vehicle types (commuter rail locomotive, commuter rail passenger coaches, and light rail vehicles), which continue to account for a growing percentage of rail transit vehicles, have remained relatively constant and, in some cases, shown marginal improvement in condition and decrease in age between 1987 and 2000. The percentage of these rail vehicle types that are overage has also declined over this period. In 2000, the average age of commuter rail locomotives was 15.8 years and their average condition 4.51. Between 1987 and 2000, their average age fluctuated between 15.3 and 16.9 years and their average condition level between 4.34 and 4.53. The average age and condition of commuter rail passenger coaches have also remained relatively constant. Between 1987 and 2000, their average condition fluctuated between 4.09 and 4.36 and their average age between 17.3 and 20.1 years. In 2000, their average condition was 4.28 and average age 17.7 years. In the case of light rail, average vehicle condition ranged from 3.55 to 3.71 between 1987 and 2000. Their average age declined from 17.2 years in 1987 to 14.9 years in 1997, subsequently rising to 18.9 years in 1999. The industry standard replacement age for light rail vehicles is 25 years.
Urban Rail Maintenance Facilities
Urban rail maintenance facilities continue to age and their condition has continued to deteriorate, although the average condition remains adequate/ fair. In 2000, urban rail maintenance facilities had an average condition of 3.18. As shown in Exhibit 3-42, almost half of all urban rail maintenance facilities are more than 30 years old, and 85 percent are more than 10 years old. The condition of these facilities, updated based on engineering surveys of 36 rail facilities in 2000 and 2001, is lower than in 1997. About 75 percent of this decline was due to methodological revisions.
The distribution of the conditions of urban rail maintenance facilities found in the most recent surveys are provided in Exhibits 3-43. Twenty-one percent of all urban rail maintenance facilities were found to be in good or better condition, and 64 percent in adequate or better condition. By comparison, the 1999 C & P Report stated that 60 percent of all urban rail maintenance facilities were in good or better condition and 77 percent in adequate or better condition. The percentage of facilities in substandard or worse condition was also found to have climbed to 36 percent in 2000 from 23 percent in 1997. Again, these changes, in part, reflect revisions to the decay curves and not solely deterioration in condition levels.
Other Urban Rail Infrastructure
The condition of urban rail infrastructure other than maintenance facilities and stations is estimated on the basis of decay curves relating condition to age, usage, and maintenance history. This information is based primarily on rail asset information collected by the Chicago Transit Authority (CTA) during the 1980s and 1990s for an Engineering Condition Assessment (ECA). Additional, but considerably more limited, asset condition data was provided by Metra and Pace, two transit operators in the Chicago area. The infrastructure data are based on the dollar amounts spent on different asset types (in constant dollars) rather than a numeric count of the assets. For this reason, condition results are displayed as percentages across condition levels rather than in units. The data collected were used to estimate decay curves for more than 40 different types of transit assets and averaged into a smaller number of aggregate decay curves, according to each asset’s contribution to the total replacement cost for the group of assets into which it was averaged. As a part of the validation process, industry experts reviewed the results and assessed whether they accurately captured the dynamics of transit asset decay. The results were published in The Estimation of Transit Asset Condition Ratings, Heavy Rail Systems, January 1996. These results supersede those from a previous survey of rail system asset conditions in nine metropolitan areas, The Status of the Modernization of the Nation’s Rail Transit Systems, June 1992. Conditions results for 1992, reported in Exhibit 3-44, are based on the earlier survey and are, therefore, not entirely comparable to those reported for 1997 and 2000. The 1992 survey was considerably smaller in scope than the one conducted by CTA.
Track conditions are estimated to have remained constant since 1997, with 83 percent of all track estimated to be in adequate or better condition in both 1997 and 2000. [See Exhibit 3-44]. The average condition of power systems appears to have improved slightly since 1997. In 2000, 88 percent of substations and overhead wire (power system components) were estimated to be in adequate or better condition compared with 82 and 84 percent, respectively, in 1997. The condition of third rail, also a power system component, has improved even more dramatically, with 83 percent estimated to be in adequate or better condition in 2000, compared with 75 percent in 1997.
Station conditions in 2000 have been calculated on the basis of newly estimated decay curves for rail maintenance facilities. While the percentage of stations estimated to be in adequate or better condition has increased from 77 percent in 1997 to 84 percent in 2000, the percentage in good or better condition has declined from 54 percent in 1997 to 34 percent in 2000. These changes have resulted from the application of the newly estimated decay curve rather than in a change in the actual condition level of stations.
The conditions of structures (elevated structures and underground tunnels) have also improved. In 2000, 77 percent of this infrastructure was estimated to be in adequate or better condition, compared with 71 to 72 percent in 1997. The condition of rail yards has declined. In 2000, 50 percent of all yards were in good condition and 50 in adequate condition compared with 63 percent in good condition and 37 percent in adequate condition in 1997.
Rural Transit Vehicles and Facilities
Data on the conditions of rural vehicles and facilities is available from surveys funded by the Federal Transit Administration and conducted by the Community Transportation Association of America. Rural operators are defined as those operators outside urbanized areas, a different definition than used by the U.S. Census. Two surveys were conducted in 1997 and 2000, with a total of 158 rural transit operators responding. The data collected ranged from June 1997 to June 1999, but have been combined for the purposes of this analysis, as shown in Exhibit 3-45. Data from the last survey, conducted in 1994, was presented in the 1999 Conditions and Performance Report.
More than 50 percent of the rural transit fleet is overage. According to transit vehicle type, 41 percent of small buses, 34 percent of medium-size buses, 27 percent of full-size buses and 60 percent of vans and other vehicles are overage.
The condition of rural bus maintenance facilities changed minimally between 1992 and 1999 [See Exhibit 3-46]. While the percentage of facilities in good or excellent condition declined marginally, from 82 to 80 percent, the percentage in very poor condition dropped from four percent in 1992 to one percent in 1999.
Special Service Vehicles
There is no current information available on the age and condition of special service vehicles. The last survey of special service vehicle ages was undertaken in 1994. This survey found that 19 percent of all medium buses were overage, 18 percent of all small buses and 43 percent of vans and other vehicles.