Conditions and Performance Chapter Listing

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Introduction

Summary

Road Conditions

Bridge Conditions

Transit System Conditions

This report represents another step in a series of improvements that have been made in recent years to the calculation of public transit asset conditions, particularly in relating the age of assets to their actual physical condition. In particular, the data presented here on bus vehicle and maintenance facility conditions have been improved by input from the 1999 National Bus Condition Assessment. Such improvements are expected to continue in the future, as more data on conditions is collected and analyzed. For more information on the National Bus Condition Assessment and the methodology used to calculate conditions, see Appendix I.

Urban Bus Fleet

Vehicle condition ratings are based on a scale from 1 (poor) to 5 (excellent) (Exhibit 3-31). The aging of the fleet can be described both by the average vehicle age and by the percentage of vehicles which are considered "overage," meaning that the vehicle's age exceeds FTA's minimum useful-life guidelines (Exhibit 3-32). Exhibit 3-33 shows the average ratings on this scale for different sizes of bus and demand response vehicles, as well as the average age and the overage percentage for each type of vehicle.

Exhibit 3-31

Bus Fleet Condition Ratings Description

Source: Transit Economic Requirements Model (TERM).

Exhibit 3-32

FTA Minimum-Useful Life Guidelines

The ratings shown here differ from those found in the 1997 Report in two significant ways:
—Estimated conditions are uniformly lower than reported in prior reports
—Average conditions for each asset type do not change as significantly over time

Both of these features are primarily due to the updated relationship between bus vehicle condition and age determined by the National Bus Condition Assessment (Appendix I). The lower ratings result from the more rapid decline in asset condition that is exhibited by the new curves, and the more stable time series reflects in part the long period of slow decay.

The estimated average condition of the urban bus fleet in 1997 is 3.1, or adequate. This represents a slight improvement over the level of 3.0, which was attained in each of the previous 9 years. Conditions for large, articulated buses have declined over the previous decade, from 3.1 to 2.7, while conditions of vans have increased from 3.2 to 3.5.

Exhibit 3-33. Urban Transit Bus Fleet Count, Age and Condition, 1987-1997

This improvement in conditions reflects the slight change in average vehicle age over the decade from 7.5 years to 6.6 years. Decreases in the average ages of vans and small and mid-sized buses have been partially offset by the significant aging of the articulated bus fleet, where the average age has increased from 4.9 to 11.8 years, and over 60 percent of these vehicles can be considered overage.

Note that the corresponding decay has not been nearly as dramatic, however, due to the relatively flat decay curve in the range from 5 to 12 years.

The average age of full-size buses, by far the most numerous bus type, is the same as it was in 1987 (8.2 years), but has decreased since 1994. Accordingly, the average condition of this predominant type remains at 3.0.