00625600

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http://onlinepubs.trb.org...trr/1992/1361/1361-030.pdf

https://scholar.google.co...llen&publication_year=1992

Engineers and planners designing at-grade light rail transit (LRT) operations typically are faced with the challenge of balancing two conflicting objectives. On the one hand, the transit authority expects LRT operations to receive full priority at all at-grade crossings in order to achieve minimum travel time. On the other hand, the agency having jurisdiction over the arterial on which the LRT runs expects to maintain normal intersection operations so that peak-hour vehicle traffic delays are not worsened by the implementation of LRT services. The proposed Central Light Rail Line (CLRL) for metropolitan Baltimore was no exception to this situation. The CLRL will ultimately be 27 mi long, with a section of approximately 1.5 mi running along Howard Street through the central business district (CBD) of Baltimore. Howard Street is a two-way, north-south nonprogressive street that intersects with a number of major arterials receiving signal progression during the peak hours. The city is concerned that the proposed LRT will degrade progression on these major arterials and cause unacceptable delays to peak-hour traffic. Using the concept of traffic progression, progressive green bands for the proposed CLRL are developed to enhance its operation and at the same time minimize its effect on cross-street traffic progression. Traffic effects of LRT operations are quantified in terms of disruptions to cross-street progression, intersection level of service, and the performance of a partial CBD street network measured by systemwide criteria. The results reconfirm a previous belief that signal progression for LRT operations is available in the current computerized traffic signal network and that full priority LRT operations along Howard Street could be designed without significantly affecting cross-street progression.

This paper appears in Transportation Research Record No. 1361, Light Rail Transit: Planning, Design, and Operating Experience (Papers presented at the Sixth National Conference on Light Rail Transit, held in Calgary, Alberta, Canada, May 24-27, 1992). Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01405036

English

p. 207-216

1992

Transportation Research Record

0309054001

Figures (7) ; References (6) ; Tables (4)

Arterial highways; Bus priority; Central business districts; Intersections; Level of service; Light rail transit; Peak hour traffic; Progressive traffic signal control; Streets; Traffic congestion; Traffic delays; Traffic signal preemption; Traffic signal timing

Baltimore (Maryland)

Baltimore (Maryland)

Highways; Planning and Forecasting; Public Transportation

TRIS, TRB

Dec 22 1993 12:00AM