| Title | Capacity and Service Analysis of Exclusive Motorcycle Lanes, Urban Bus Transit Facilities, and Urban Arterials (3/3) |
| Dept | Transportation Planning and Land Transport Division |
| Year | 2010 |
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| Summary | In 2006 the Institute of Transportation, Ministry of Transportation and Communications, initiated a three-year project to revise three chapters of the 2001 Taiwan Area Highway Capacity Manual. The first phase and the second phase of the project focus respectively on Chapter 18 Motorcycle Lanes and Chapter 16 Urban Streets. These two phases have been completed. The third phase of the project, which is the subject of this report, is devoted to the revision of Chapter 17 Urban Bus Transit Systems. This phase includes the following tasks: (1) literature review on capacity analysis of urban bus transit operations (2) field investigation of the operating characteristics of the urban transit systems in Taiwan (3) calibration of the Highway Traffic Systems Simulation (HTSS) Model for use as an analysis tool (4) analysis of the characteristics of the segment capacities of bus routes (5) revision of Chapter 17 and (6) field investigation of the speed-flow relationship on rural two-lane highways. Field data reveal several important operating characteristics of bus transit systems. First, the average free-flow speed of urban buses is approximately 40 km/h. Second, the queue discharge rate at the stop line of a signalized intersection depends on the queue positions of buses, but it can reach approximately 1,200 buses/h/lane. The corresponding straight-through small vehicle equivalent of buses is about 1.7. Third, bus drivers tend to stop wherever passengers stand and thus reduce the efficiency in utilizing the space at a bus stop. This can result in a capacity reduction of about 10% for an exclusive bus lane. Fourth, the average fare payment times vary from about 1.9 s for cash payment and non-contact smart-card payment to about 4 s for discount- ticket payment. And, finally, the average dwell time of buses at a bus stop rarely exceed 40 s, and individual dwell times follow a well-defined probability distribution. The field data collected on a rural two-lane highway do not reveal the speed-flow relationship when flow is near capacity. Nevertheless, they show that the average fee-flow speed on a two-lane highway can be as much as 20 km/h above the speed limit. The field data on bus operations are used to calibrate the HTSS model and the resulting model can provide realistic estimates of the segment capacities of exclusive bus lanes. With the help of simulation output, an analytical model is developed to simplify the estimation of segment capacities of exclusive bus lanes. The revised Chapter 17 incorporates the findings of the third phase of the project. It uses the following measures of effectiveness to evaluate urban transit bus operations: (1) average service headway (2) on-time performance (3) average floor area occupied by each on-board passenger (4) average stopped delay and (5) average travel speed. |
| Post date | 2010/11/29 |
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