Benefit

Queue jumper transit signal priority (TSP) can reduce bus delay by 3 to 17 percent over mixed-traffic TSP design.

Results of queue jumper lane microsimulation.



Summary Information

Transit signal priority (TSP) systems generally operate in mixed-traffic lanes, which can limit the effectiveness of TSP deployments, particularly during heavy volume peak hours when the system is most needed. This microsimulation compared several measures of effectiveness for TSP with mixed-traffic vs. queue jumper lanes, as well as near-side vs. far-side stop placement. Queue jumper lanes allow buses to bypass queues at traffic signals, similar to that of a bus lane, but then requires the vehicle to merge back into mixed-traffic lanes after the signal. The objectives of this paper are twofold. The first objective is to propose an actuated TSP strategy and its associated signal control designs for a queue jumper lane. In an actuated TSP strategy, a priority signal is provided only when a request from a bus is detected. The second objective is to evaluate the performance of the proposed queue jumper TSP strategy by comparing it with the general actuated mixed-lane TSP. The next section presents the design of various signal design elements for TSP and queue jumper lanes, including phasing, phase splits, multiple bus services, and coordination recovery and green reimbursement. This is followed by the implementation of the proposed designs in a simulation testbed for a performance evaluation with mixed-lane TSP.

Method
This study focused on four average travel delay measures of effectiveness: bus vehicle delay, major-street through vehicle delay, minor-street through vehicle delay, and intersection vehicle delay. Four operational scenarios were tested: mixed-traffic TSP with near-side stop, mixed-traffic TSP with far-side stop, queue jumper TSP with near-side stop, and queue jumper with far-side stop. For each operational scenario run, all factors remained constant except either major-street bus volume or major-street through volume. Each run was conducted for a simulated two hours of traffic operations.

Findings
  • The simulation results show that queue jumper TSP with a near-side bus stop can reduce bus delay by 3 to 17 percent when compared to mixed-lane TSP with a far-side bus stop, which was the most commonly used TSP design.
  • The simulation results also showed that queue jumper TSP reduces bus delay by 25 percent with near-side bus stop placement instead of far-side bus stop placement.
These advantages in type of TSP and stop placement were more prevalent in high traffic volumes. The simulation results showed that general traffic on the major streets can also benefit from the use of the TSP queue jumper lanes. Adverse impacts on cross streets were mitigated due to constraints on TSP requests to only impact no more than two consecutive signal cycles. The measure of bus delay was the only measure where the different technologies and stop placement made a significant difference.

Benefit Comments

No comments posted to date

Comment on this Benefit

To comment on this summary, fill in the information below and click on submit. An asterisk (*) indicates a required field. Your name and email address, if provided, will not be posted, but are to contact you, if needed to clarify your comments.



Source

Design of Transit Signal Priority at Signalized Intersections with Queue Jumper Lanes

Author: Guangwei Zhou, Albert Gan

Published By: Journal of Public Transportation, Vol 12, no. 4

Source Date: 2009

URL: http://www.nctr.usf.edu/jpt/pdf/JPT12-4Zhou.pdf

Rating

Average User Rating

0 ( ratings)

Rate this Benefit

(click stars to rate)


Goal Areas

Mobility

Typical Deployment Locations

Metropolitan Areas

Keywords

bus priority, traffic signals, TSP

Benefit ID: 2014-00902