Benefit
A nationwide survey evaluating overheight/oversize warning systems found that eight states that deployed active infrared light or laser activated warning systems had fewer overheight load strikes on infrastructure components.
12-16 January 2003
Nationwide,United States
Summary Information
A nationwide survey of 29 state DOTs examined the state-of-the-art practice for oversized vehicle warning systems. Overheight loads pose a significant hazard to the infrastructure that they must pass under and through. Frequently, damaged infrastructure or vehicles may fall onto nearby vehicles or onto the traveled surface, posing a considerable safety concern and requiring extensive and expensive repair. Each state Department of Transportation (DOT) may select a variety of strategies to try to mitigate overheight vehicles crashing into the infrastructure. Many state DOTs focus on effective routing strategies for permitted vehicles; however, at times routing errors may still occur. Furthermore, drivers may actually disregard the routing instructions or fail to follow them due to an error. These concerns make the need for redundancy within the system more critical. This paper examines the strategies that a state DOT may select to create this redundancy in the system to improve safety and reduce maintenance costs. These strategies include passive and active systems which is the primary focus of this paper.
Much of recent research regarding oversize vehicles has focused on developing an automatic procedure for routing these vehicles using a geographic information system (GIS) (1). This focus does not immediately solve the infrastructure crash problem because the current bridge collisions occur when the vehicles fail to obtain the proper oversize permits or ignore the required route provided by their permit. This does not eliminate the need for safe routing procedures because a routing error may cause significant damage or loss of life (2).
This research attempts to synthesize existing data and previous research to develop a comprehensive examination of the state-of-the-practice for oversized vehicle warning devices. The lack of primary data sources and previous research requires much of the analysis to rely on anecdotal data and qualitative assessments. To gather data, telephone interviews were conducted with 31 State DOTs. To supplement the data, interviews were also conducted with some vendors. Of the 31 states contacted, 29 completed the interview process with only 11 states using some form of overheight warning system. The participating states used a wide range of warning systems. They included blockades before tunnels to laser activated early warning detection systems. The initial interviews were supplemented with email and fax correspondence. After completing the surveys, two site visits were held in California and Pennsylvania. The site visits included active detection systems located near tunnels as well as at weigh stations. No passive devices were included in the data collected.
FINDINGS
(2) Mehta, S. and P. Willon. Caltrans Routing Errors Behind 3 Crashes. LA Times, Orange County Edition, July 23, 1999, pp. 1.
Much of recent research regarding oversize vehicles has focused on developing an automatic procedure for routing these vehicles using a geographic information system (GIS) (1). This focus does not immediately solve the infrastructure crash problem because the current bridge collisions occur when the vehicles fail to obtain the proper oversize permits or ignore the required route provided by their permit. This does not eliminate the need for safe routing procedures because a routing error may cause significant damage or loss of life (2).
This research attempts to synthesize existing data and previous research to develop a comprehensive examination of the state-of-the-practice for oversized vehicle warning devices. The lack of primary data sources and previous research requires much of the analysis to rely on anecdotal data and qualitative assessments. To gather data, telephone interviews were conducted with 31 State DOTs. To supplement the data, interviews were also conducted with some vendors. Of the 31 states contacted, 29 completed the interview process with only 11 states using some form of overheight warning system. The participating states used a wide range of warning systems. They included blockades before tunnels to laser activated early warning detection systems. The initial interviews were supplemented with email and fax correspondence. After completing the surveys, two site visits were held in California and Pennsylvania. The site visits included active detection systems located near tunnels as well as at weigh stations. No passive devices were included in the data collected.
FINDINGS
- Eight of 11 states deploying active overheight warning systems believe their systems reduce overheight loads striking infrastructure components.
- The study found that even though data was anecdotal, the findings still merit consideration because results tended to be fairly uniform across the responding states with active warning systems.
(2) Mehta, S. and P. Willon. Caltrans Routing Errors Behind 3 Crashes. LA Times, Orange County Edition, July 23, 1999, pp. 1.
Goal Areas
Typical Deployment Locations
Statewide
Keywords
None defined
Benefit ID: 2008-00514
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