scholarly journals Phase Force-off Modes in Coordinated-Actuated Signal Operations

2016 ◽  
Vol 83 ◽  
pp. 600-606 ◽  
Author(s):  
Jisun Lee
Keyword(s):  
Actuated Signal ◽  
Signal Operations

Actuated Signal Operations of Congested Diamond Interchanges

2006 ◽  
Vol 132 (10) ◽  
pp. 790-799 ◽  
Author(s):  
Sangsoo Lee ◽  
Carroll J. Messer ◽  
Keechoo Choi
Keyword(s):  
Actuated Signal ◽  
Diamond Interchanges ◽  
Signal Operations

Estimating Pedestrian Impact on Coordination of Urban Corridors

2019 ◽  
Vol 2673 (7) ◽  
pp. 265-280 ◽  
Author(s):  
Sharmin-E-Shams Chowdhury ◽  
Aleksandar Stevanovic ◽  
Nikola Mitrovic
Keyword(s):  
Cycle Length ◽  
Network Performance ◽  
Traffic Signals ◽  
High Fidelity ◽  
Vehicular Traffic ◽  
Traffic Demand ◽  
Advantages And Disadvantages ◽  
Street Traffic ◽  
Pedestrian Impact ◽  
Signal Operations

Pedestrian walk timings at most U.S. traffic signals are run in concurrence with relevant signal phases for vehicular traffic. This usually means that signal operations coordinated for the major street can be interrupted by a pedestrian call. Such an interruption may in practice last for a few minutes, thus causing increased delays and stops for major traffic flows. An alternative to this design is to increase the cycle length and embed pedestrian timings within the ring-barrier structure of the prevailing coordination plan. Both approaches have advantages and disadvantages. A fresh approach offered by this study is a comprehensive experimental design and holistic performance evaluation perspectives. The study examines the two abovementioned treatments of pedestrian timings for a small corridor of five intersections in Utah. The experiments have been done in a high-fidelity microsimulation environment with the Software-in-the-Loop version of the field controller (Econolite ASC/3). Findings show that either approach works well for very low traffic demands. When the traffic demand increases findings cannot be generalized as they differ for major coordinated movements versus overall network performance. While major-street traffic prefers no interruption of the coordinated operations, the overall network performance is better in the other case. This can be explained by the fact that avoiding interruptions is usually achieved at the expense of longer cycle length, which increases delay for everyone in the network.

Impact of Detector Configuration on Performance Measurement and Signal Operations

2020 ◽  
Vol 2674 (4) ◽  
pp. 300-313
Author(s):  
A. M. Tahsin Emtenan ◽  
Christopher M. Day
Keyword(s):  
Performance Measures ◽  
Situational Awareness ◽  
Performance Measure ◽  
Detection Zone ◽  
Zone Length ◽  
Single Detector ◽  
Detector Configurations ◽  
Proxy Measurement ◽  
The Impact ◽  
Signal Operations

In recent years, automated traffic signal performance measures (ATSPMs) have emerged as a means of developing situational awareness of traffic conditions at intersections and assessing the quality of signal operations. As a growing number of agencies are adopting the technology, there is a need to understand how detector configurations can influence the outcomes of an analysis using ATSPM. Current practices with regard to detector configuration vary considerably from one agency to another; at one extreme, agencies may use one single detector input channel per phase without considering where the detectors are located, whereas at the other extreme, some agencies may utilize all possible channels to observe each individual lane at multiple positions. There are also variations in the design of detection zones (lengths and positions). This study takes on the problem in two parts. The first of these examines the impact of stop bar detection zone length and lane- or approach-based detector assignment on the ability of performance measures to identify accurately whether split failures occur. The second part examines the impact of setback detector distance on the use of a “percentage on green” metric that serves as a proxy measurement of the number of stops. The paper presents recommendations for performance measure calibrations and detector configurations that follow from these outcomes.

Driver Age as a Factor in Comprehension of Left-Turn Signals

1997 ◽  
Vol 1573 (1) ◽  
pp. 76-85 ◽  
Author(s):  
Aris Drakopoulos ◽  
Richard W. Lyles
Keyword(s):  
Correct Answer ◽  
Explanatory Variable ◽  
Age Groups ◽  
Error Rates ◽  
Original Study ◽  
Older Drivers ◽  
Left Turn ◽  
Turn Signal ◽  
Right Of Way ◽  
Signal Operations

An experiment to measure driver comprehension of left-turn signal and sign configurations was conducted as part of a study to investigate the performance of left-turn signals used in various signal strategies. The responses of 191 individuals to 81 stimuli simulating left-turn signal phases were analyzed for the effect of signal message on driver comprehension. Stimuli included 17 left-turn signal displays used for permitted, protected, and protected/permitted left-turn strategies as well as left turns during nighttime or emergency flashing signal operations. Comprehension in the original study was based on a correct versus incorrect dichotomy: if the subject’s response agreed with a predetermined subset of possible answers, the answer was correct; all other answers were considered incorrect. These data are reanalyzed with three principal variations: ( a) individuals’ answers are based on a three-level correctness concept whereby answers considered incorrect in the previous study were further categorized into minor errors and serious errors depending on whether subjects incorrectly chose to “give away” their right-of-way or to violate other drivers’ right-of-way, respectively; ( b) signal message is introduced in the analysis as an explanatory variable of driver comprehension; and ( c) emphasis is placed on older drivers. Youngest, oldest, and female subjects were found to drive fewer kilometers per year than middle-aged males. Comprehension was found to deteriorate with driver age in terms of both higher serious error rates and lower correct answer rates. Flashing signals were the least well understood, whereas change and red interval stimuli were understood best by all age groups.

Sign in / Sign up

Export Citation Format

Share Document