When Peaks are PlateausApril 17, 2012 by: Samuel Scheib
Peak hour, whether by motorcars as recorded by traffic counters or as additional vehicles put into service by transit agencies, takes its name from the way these data points appear on a graph. In the morning and late afternoon more people use roads and usually more transit is provided so those periods have predictable spikes. Not every transit agency has those peaks in service, including the one where I work, and this caused some questions lately with respect to charter service.
This post might have been of the “They say” variety because they say a recipient cannot provide charters during peak hours. Such a rule would have a significant impact on a transit system that either has no peak or an all-day peak, depending on one’s perspective. But it turns out this rule no longer exists. They say a recipient cannot provide peak-hour charter service because they worked when that was true. In 1987, CFR 49 Part 604 read in part:
(i) Incidental Charter Service means charter service which does not: (1) interfere with or detract from the provision of the mass transportation service for which the equipment or facilities were funded under the Acts; or (2) does not shorten the mass transportation life of the equipment or facilities.
Interfere or detract was frequently interpreted to mean peak hour. To use an example, in 2004, the Ohio DOT put out a charter handbook that said any charter service provided by the transit system must be “incidental.” And then: “Examples of what would not be ‘incidental’ may include: service performed during peak hours.”
Having gone over the revised 2008 charter regulation many times, I am sure this language has been removed and nothing similar is in its place. My read is that there is no prohibition on peak-hour charter service. Arriving at this conclusion, I was still curious as to what peak-hour means in the context of all-day service frequencies.
From the FTA triennial review workbook we get the method for determining the spare ratio:
Number of vehicles required for maximum service. Use the revenue vehicle count during the peak season of the year on the week and day that maximum service is provided, excluding atypical days and one-time special events.
This is a long way of describing a measure used by the National Transportation Database (NTD) and reported by transit agencies, vehicles operating in maximum service (VOMS). If VOMS is the standard for what a peak is, then running the same headways all day means all-day peak, a plateau really. But later in the same workbook under Half Fare we find that, “The grantee determines its peak hours. Peak hours can be seasonal. If the grantee determines it is not large enough, or demand is not strong enough, to identify or justify peak hour service, then its entire service should be defined as ‘off peak.’ In this instance, the grantee has two options: Review ridership data and determine the peak ridership hours and develop a policy for half fare, or choose not to determine a peak period and offer half fares during all hours.”
FTA is stating plainly that the grantee can determine its peak, and also that the grantee can simply look at the period when people ride the most and say that is the peak. Periods of max ridership are likely to be correlated to VOMS (peak vehicles); it is very unlikely ridership would be higher in periods when fewer buses are deployed than when more are, perhaps even impossible. But, again, if headways don’t change that correlation disappears entirely. Peak hour, it seems, is whatever you want it to be.