Click for next page ( 32

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 31
31 turns onto it. The traffic on 9th and 10th is controlled by traf- fic lights that turn red for pedestrians and for trains. They are experiencing drivers running the red lights at O Street. Gen- erally, the drivers stop at the lights to look for pedestrians; however, when they do not see any pedestrians, some decide to run the light, not realizing a train is coming. The collision is a right-angle collision between the LRVs and the motor vehicles. In rare cases, a motorist does not stop at all and gets struck by the train in the intersection. Sacramento RT hypothesized that this may be a result of the traffic signal progression provided along 9th and 10th Streets. In other words, drivers may be expecting the lights at O Street to turn FIGURE 34 12th Street mixed-use right-of-way in Sacramento green as they are approaching; however, if the train has pre- (Courtesy: Sacramento Regional Transit District). empted the signal, the light will not be green as expected; therefore, motorists run the light and a collision occurs. Although they cannot confirm this, Sacramento RT suspect that this is a factor in at least some of the collisions. drivers making left turns from the "#2 lane" (instead of mak- ing left turns from the lane shared with the train) are being struck by the train in the adjacent lane traveling in the same DALLAS AREA RAPID TRANSIT direction. There is no signage indicating lane assignments and permitted movements; however, there are pavement markings DART operates more than 40 miles of light rail, most of which (arrows) in each lane that indicate the permitted movements. is located in exclusive right-of-way. Motor vehicles and LRVs Possible issues with the pavement markings are that they have are, however, controlled exclusively by traffic signals in faded and, when vehicles are stopped at the light, drivers two different environments, a median-running segment of the might not be able to see them. Sacramento RT has requested South Oak Cliff Line and the central business district Transit- that the city add lane-use signs to indicate lanes and permitted way Mall in downtown Dallas. The segment of the South Oak movements. There is a flashing yellow associated with the Cliff Line that is controlled by traffic signals is approximately outbound train, and they have not had a problem with colli- 2-miles long and runs in the middle of a four-lane divided arte- sions between left-turning motorists and LRVs traveling in rial (median-running). The LRT track is separated from the the opposite direction. motor vehicle travel lanes by a raised barrier curb. There are 12 at-grade crossings in the 2-mile segment. This section was part of a system expansion in 1997. After the expansion, Pedestrian Mall DART began experiencing a number of collisions between LRVs and motorists making illegal left turns across the tracks Another location where they are experiencing problems is from the protected left turn. Although lead-lag left-turn opera- downtown at the intersections of 9th and 10th and O Streets. tions are normally preferred to improve progression along Because there is a pedestrian mall along O Street; motorists the arterial, dual left-turn phasing was implemented to improve traveling along 9th and 10th streets are not allowed to make compliance with the left-turn restriction. Even with these FIGURE 35 12th Street and E Street: Vehicle occupying shared lane (left) and LRV occupying shared lane (right) (Courtesy: Sacramento Regional Transit District).