Details:

Creators:
Sun, Carlos ; Edara, Praveen ; Hou, Yi ; Robertson, Andrew
Sun, Carlos ; Edara, Praveen ; Hou, Yi ; Robertson, Andrew Less -
Corporate Creators:
University of Missouri--Columbia. Dept. of Civil and Environmental Engineering
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Benefit Cost Analysis Field Studies Merging Traffic Night Visibility Speed Control Tapers (Work Zone Traffic Control) Warning Signals Work Zone Safety
Resource Type:
Tech Report
Geographical Coverage:
Missouri
Corporate Publisher:
Smart Work Zone Deployment Initiative
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION;NTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control Devices;NTL-SAFETY AND SECURITY-Highway Safety;
Abstract:
Improving safety at nighttime work zones is important because of the extra visibility concerns. The deployment of sequential lights is an innovative method for improving driver recognition of lane closures and work zone tapers. Sequential lights are wireless warning lights that flash in a sequence to clearly delineate the taper at work zones. The effectiveness of sequential lights was investigated using controlled field studies. Traffic parameters were collected at the same field site with and without the deployment of sequential lights. Three surrogate performance measures were used to determine the impact of sequential lights on safety. These measures were the speeds of approaching vehicles, the number of late taper merges and the locations where vehicles merged into open lane from the closed lane. In addition, an economic analysis was conducted to monetize the benefits and costs of deploying sequential lights at nighttime work zones. The results of this study indicates that sequential warning lights had a net positive effect in reducing the speeds of approaching vehicles, enhancing driver compliance, and preventing passenger cars, trucks and vehicles at rural work zones from late taper merges. Statistically significant decreases of 2.21 mph mean speed and 1 mph 85% speed resulted with sequential lights. The shift in the cumulative speed distributions to the left (i.e. speed decrease) was also found to be statistically significant using the Mann-Whitney and Kolmogorov-Smirnov tests. But a statistically significant increase of 0.91 mph in the speed standard deviation also resulted with sequential lights. With sequential lights, the percentage of vehicles that merged earlier increased from 53.49% to 65.36%. A benefit-cost ratio of around 5 or 10 resulted from this analysis of Missouri nighttime work zones and historical crash data. The two different benefit-cost ratios reflect two different ways of computing labor costs.
Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:fe60f9fcbb3649f9a260b1a8de1ae79e97cfd6e11a390075df01b9c8f0e2981a
Download URL:
https://rosap.ntl.bts.gov/view/dot/23517/dot_23517_DS1.pdf
File Type:

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