The Oregon DOT evaluated work zone intrusion alert systems in three paving projects.
Columbia County, Oregon, United States
Hood River County, Oregon, United States
Wasco County, Oregon, United States
Summary Information
This research evaluated three commercially available work zone intrusion alert technologies in field testing to assess current cost and feasibility of implementation. Due to difficulty in assessing benefits of each system, the cost analysis does not consider variations in benefits in terms of lowering overall risk to work zone workers.
The cost of implementing each technology were estimated for a 1-mile highway work zone with closure of a 12-foot wide lane. Costs for moving the system to a new location as paving progressed or retrieving the system at the end of the project were not included in the estimates.
Systems A and B
For two of the systems, the number of sensors is related to the number of cones and spacing. Using the maximum allowable cone spacing for a 35 mph speed limit (35-foot spacing) it was estimated that approximately 14 cones equipped with this system would cover 400 feet in advance of an active work area. If cone spacing was reduced to 20 feet to further reduce the possibility of a car intruding into the work zone without hitting the cones, 22 cones would be required (20 longitudinal along the lane line, and 2 transverse across the lane).
Equipment cost |
14 cones |
22 cones |
System A |
$1,260 |
$1,980 |
System B | $2,400 | $3,200 |
System C
The third system used a different approach and did not require equipment to be integrated into traffic cones, but instead covers the intrusion path preceding the work zone area using pneumatic tubes. The total cost for a system designed to cover a 400-foot section of roadway in advance of a work area was estimated at $5,940. This included a total of eight 50-foot long pneumatic vehicle detection tubes and the associated equipment attached to each hose.
Work Zone Intrusion Alert Technologies: Assessment and Practical Guidance
Work Zone Intrusion Alert System: $1,260 - $5,940 covering a 400-foot approach to a work area with single lane closure.