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BUS FREQUENCY DETERMINATION PASSENGER COUNT DATA
of Civil Engineering, Transportation Research Institute, Tcchnion-Israel Technology, Haifa, Israel (Received 21 February 1983; in revised form 5 December 1983)
Abstract-The importance of ridership information has led transit properties to increase the amount of manually collected data or alternatively to introduce automated surveillance techniques. Naturally, the bus operators are expected to gain useful information for operations planning by obtaining more accurate passenger counts. This paper describes and analyzes several appropriate data collection approaches for the bus operator in order to set the bus frequencies/headways efficiently. Four different methods are presented to derive the bus frequency: two are based on point check (maximum load) data and two propose the use of ride check (load profile) data. A ride check provides more complete information than a point check, but at a greater cost, and there is a question as to whether the additional information gained justifies the expense. Based on available old profiles, the four methods provide the bus scheduler with adequate guidance in selecting the type of data collection procedure. In addition, the scheduler can evaluate the minimum expected bus runs when the load standard is released and avoid overcrowding (in an average sense) at the same time. Alternative timetables are also investigated in conjunction with minimizing the required bus runs and number of buses for a single route. In this way, the derived headways can be analyzed within an acceptable range while considering the possible changes incurred indirectly to the fleet size. The integration between resource. saving and frequency determination procedures allows the scheduler’s performance to be improved.
1. IN7’RODUCI’ION AND ORJECTIVES
It is well known that transit demand varies systematically by season, day-of-the-week, time of day, location and direction of travel. However, the absence of accurate data on travel patterns at the route level has made it impossible to deploy transit resources to match these variations and thus to increase the efficiency of system operation. Accurate ridership information is needed for transit planning and scheduling and also to comply with external reporting requirements (e.g. Section 15 of the U.S. Urban Mass Transportation Act). Consequently, some transit operators have started to use automatic passenger counters while others are adding more checkers to collect the data manually. The primary objective of passenger counts, from the transit operator’s viewpoint, is to set vehicle frequencies/headways efficiently on each route. Other uses of ridership information are in revenue estimation and measurement of dynamic patronage trends. The topic addressed in this paper is two-fold. The first segment involves the setting of bus frequencies in order to maintain adequate service quality and minimize the number of buses required by the schedule. The second is an evaluation tool to efficiently allocate the cost for gathering appropriate passenger load data at the route level. It is common to almost all bus operators worldwide for load profile information along the entire iThis study was written while the author was in 1982 at the Transportation Systems Center (IX), Cambridge, Massachusetts, U.S.A. TSC Support is gratefully acknowledged. 439
length of the bus route (ride check) to be gathered annually or every few years. Usually the most recent passenger load information will be at one or more selected stops along the route where the bus carries its heaviest loads (point check). A ride check provides more complete information than a point check, but is more expensive because either additional checkers are needed to provide the required data or an automated...