Knowledge Resources

An automated workzone information system (AWIS) was deployed near Los Angeles, California on Interstate 5 between Magic Mountain Parkway and Rye Canyon Road. One southbound lane and one northbound lane adjacent the median were closed leaving three lanes in each direction open to motorists. The AWIS included vehicle detectors and three portable dynamic message signs (DMS). During traffic congestion, DMS messages suggested that drivers exit the freeway and use an alternate arterial route, the Old Road. Based upon detected traffic conditions in southbound lanes, the following messages were displayed on the DMS:

• TRAFFIC JAMMED alternating with SOUTH 5 AT RYE CANYON.
• SLOW TRAFFIC AHEAD alternating with PREPARE TO STOP.
• TRAFFIC JAMMED NEXT 2 MI alternating with EXPECT 5 MIN DELAY.
• TRAFFIC JAMMED AHEAD alternating with 126 FWY TO MAGIC MOUNTAIN.
• SOUTH 5 TRAFFIC JAMMED alternating with AUTOS USE NEXT EXIT.
• JAMMED TO MAGIC MOUNTAIN alternating with EXPECT 10 MIN DELAY.
• JAMMED TO MAGIC MOUNTAIN alternating with EXPECT 15 MIN DELAY.
• TRAFFIC JAMMED TO MAGIC MTN alternating with AVOID DELAY USE NEXT EXIT.
• TRAFFIC JAMMED ROUTE 126 TO MAGIC MTN.
• SOUTH 5 ALTERNATE ROUTE alternating with AUTOS USE NEXT 2 EXITS.
  
  To assess customer satisfaction, a postcard-based survey was designed to obtain driver comments on the work zone information system. At two off-ramps, Caltrans staff and California Highway Patrol officers distributed approximately 400 surveys to drivers on July 6, 2003. One hundred (100) completed surveys were received. The survey response rate was 25 percent. Survey results indicated that most respondents liked the system. Seventy-eight (78) percent of respondents changed their route based on DMS information. Seventy (70) percent of respondents thought that the DMS were useful for providing information. Sixty-three (63) percent felt that the messages were useful for providing alternative routes. Fifty-three (53) percent of respondents thought that messages were useful for avoiding delay.