Arizona tackles work zone delays: the Southwest contributes two innovative operational enhancements that might help keep traffic flowing smoothly during your construction projects

Public Roads, May-June, 2002 by Alan Hansen

If you're having trouble minimizing traffic delays during construction projects (and who isn't), then you may discover some ideas in two innovative programs developed by the Arizona Department of Transportation (ADOT)--a motorist assist patrol and a travel-time incentive program. ADOT used the new approaches to minimize motorist delays while reconstructing a 1 3-mile (21-kilometer) section of State Route 68 (SR-68). The project started in July 2000 with a partnering workshop between the contractor and ADOT, and all of the pavement was in place by the end of April 2002.

Although SR-68 is a rural corridor cutting through high-desert landscape e and the Black Mountains, highway officials in Arizona consider the road to be a major commuter route. It serves motorists traveling between Kingman and Bullhead City on the Colorado River near the State's western border. In addition to commuter traffic, trucks comprise 7 percent of the vehicles on SR-68, and a significant number of recreational users also travel the corridor. The construction project started at about the mid-point of SR-68 and went to Bullhead City

ADOT's Kingman district engineer Debra Brisk developed the motorist assist patrol and the travel-time incentive program specifically for this project. ADOT resident engineer Jennifer Livingston conducted a site visit in May 2001 when the project was approximately 35 percent complete. "The traffic management toolsr says Livingston, "truly minimized the construction impacts to the traveling public and commuters."

Motorist Assist Patrol

The motorist assist patrol (MAP) consisted of a vehicle and driver equipped with equipment and supplies that could aid stranded motorists get back on the road or call for additional assistance if needed. Each MAP vehicle was outfitted with traffic control devices, water, gasoline, flares, jacks, and lighted arrow boards.

In addition to helping the motorist safely back on the road, the MAP also kept the roadway clear, identified incidents, and maintained smooth operations while the highway was under construction. The drivers of the MAP vehicles were trained as security guards, but they dressed in typical construction-type clothing, including hard hats and safety vests.

The contractor, who operated the MAP from 4 p.m. to 6 a.m. on weekdays and around-the-clock on weekends, hired a private security guard service. They operated the MAP vehicles during the hours when construction was not going on. During construction hours, the MAP was considered unnecessary since plenty of people were available to assist motorists.

Because the MAP operated at off-peak hours and the MAP drivers approached stopped vehicles and sometimes encountered people acting suspiciously, the contractor determined that trained security guards would be safer MAP drivers. The security guard training also helped the drivers know how to approach stranded motorists in a professional manner that put the motorist at ease.

Between the program's inception in October 2000 and April 2002, the MAP vehicles assisted 963 stranded motorists. The majority of the travelers were stranded due to mechanical failure, probably caused by the high-desert temperatures and the 6-percent grade that is characteristic of much of the segment of road that was under construction. Of these motorists, 68 percent were able to get back on the road with the assistance of the MAP only. Further assistance, such as towing services, were called in the cases of the other 32 percent of the motorists needing help.

"The commitment to safety and cooperation ... by the SR-68 team was impressive," says Lieutenant Ron DeLong of the Arizona Department of Public Safety (DPS). "The Motorist Assist Patrol was very helpful to DPS and the traveling public. ADOT and the contractor also responded quickly to other travel and safety issues throughout the project."

Travel-Time System Incentive Program

The SR-68 project also implemented a travel-time system that measured the consistency of the time it took for motorists to travel through the construction work zone. Prior to construction, the average travel time for this segment, which has a posted speed limit of 55 miles per hour (89 kilometers per hour), was 17 minutes. During construction, traffic control measures and reduced posted speed limits of 35 to 45 mph (56 to 72 kin! h) increased the corridor travel time to approximately 21 minutes.

The contract included a provision that during construction, the average travel time would not exceed 27 minutes. The onus was on the contractor to measure the travel time and ensure that the average travel-time goals were met. The contract provided for a $400,000 travel-time incentive budget item that was to be reduced if the target travel-time average was exceeded. The travel times were taken 24 hours a day, 7 days a week, and were averaged over 10-minute periods. If three consecutive 10-minute periods were clocked at over 27 minutes, the contractor was charged $21.50 per minute per lane.

Any funds left in the travel-time budget are to be paid as profit to the contractor. If the contractor were unable to maintain the target travel time during construction, the entire $400,000 could be depleted, and the contractor would be responsible for paying for the additional travel-time delay.