Evaluation of Adaptive Signal Control Technology - Volume 3: Comparison of TBC 2017 and ASCT 2017

Benekohal, Rahim F.; Garshasebi, Behnoush; Jeon, Hongjae; Shang, Mingfeng

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https://hdl.handle.net/2142/103404 Copy

Description

Title

Evaluation of Adaptive Signal Control Technology - Volume 3: Comparison of TBC 2017 and ASCT 2017

Author(s)

• Benekohal, Rahim F.
• Garshasebi, Behnoush
• Jeon, Hongjae
• Shang, Mingfeng

Issue Date

2019-03

Keyword(s)

• Adaptive traffic signals
• ASCT
• signalized intersections
• corridor travel time
• traffic coordination
• field data on delay
• queue length
• HCM
• saturation flow
• signal timing

Abstract

Data were collected at five intersections along the Neil Street corridor in Champaign, Illinois, before deployment of SynchroGreen, an adaptive signal control technology (ASCT). The volume, delay, and queue length data from the field for TBC (time based coordination) 2017 conditions were compared to the data from ASCT (adaptive signal control technology) 2017 conditions, at the 97% confidence level. The field volumes were compared for 57 lane groups (approaches). Traffic volume on 7% of the lane groups significantly increased, on 72% remained unchanged, and on only 21% significantly decreased. Stopped delays increased in 56% of the cases, remained unchanged in 40%, and decreased in 4%. Queue length increased in 35% of the cases and remained unchanged in 65%. To determine ASCT performance, the changes in volume, delay, and queue length combined were considered. An overall performance indicator (PI) was determined for each approach of each intersection at each time period. The performance indicators were Imp (Improved), Unch (Unchanged), and Det (Deteriorated), with 91% confidence. One lane group was excluded from further analysis due to insufficient volume; of the 56 lane groups analyzed, 5% showed improvement, 32% remained unchanged, and 63% (35 cases) showed deterioration. Out of 35 cases, deterioration in 20 cases could be explained by contributing factors such as frequency of unfavorable arrival types under ASCT 2017, as compared to TBC 2017; a few cases of volume increase under ASCT 2017; ASCT miscount of traffic volumes; signal timing changes under ASCT 2017; and increased proportion of vehicles stopped under ASCT 2017. However, in the 15 remaining cases, there was no reasonable explanation for the PI deteriorations when ASCT was operating

Publisher

Illinois Center for Transportation/Illinois Department of Transportation

Series/Report Name or Number

FHWA-ICT-19-003

ISSN

0197-9191

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/103404

Sponsor(s)/Grant Number(s)

IDOT-R27-127

Copyright and License Information

No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161.

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