Abstract
This experiment was conducted to examine the effects a priority strategy had on the operations of an intersection in a coordinated signal system. A priority strategy was first developed for the intersection then implemented and evaluated. A second objective of the experiment was to develop an evaluation methodology which could be used by engineers to determine how a priority strategy would operate prior to implementation. The priority strategy developed used two methods to benefit bus movement. One method, green extension, lengthened the green time on the arterial to allow passage of the bus. The other, early start, shortened the cross-street period allowing the arterial phases to begin earlier than normal. Both treatments performed as expected. Another expected result of the experiment was that the strategy operated without disrupting coordination of the signal in the system (i.e. the controller did not go "off line"). The evaluation methodology developed for the experiment used the 1985 Highway Capacity Manual delay equation. Required input data includes number of lanes for each movement, hourly volumes, saturation flow rates, cycle length, and effective green times. To model the operation of the chosen priority strategy, green times were adjusted to reflect the type of treatment being used. Despite the limited data sets, the model showed encouraging results.
Beasley, Phillip Scott (1995). Analysis of a conditional active bus priority strategy in a coordinated signal system. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -B43.