8 Work Zone Safety
8.2.2 Variable Speed Limit Signs in Work Zones – Minnesota
Description of the System
The objective of the system is to make work zone speed limits on high volume urban freeways easier to sign and enforce. While this portable system is designed for deployment in urban areas, it could also be deployed in rural areas.
The system incorporates two BRICK® modular message blocks on each speed limit sign that is placed in a work zone. The signs are easily moved since they are mounted on simple U-channel supports. While construction workers are not present, the speed continues to be 105 km/h. However, when construction workers arrive, a designated worker changes the speed limit to 72 km/h.23 The displayed speeds are enforceable.
System Performance
The application is at the demonstration phase.
System Effectiveness Evaluation
The application is at the demonstration phase. In 2000, Minnesota DOT put out 1 sign for the demonstration, but they were impressed enough with the system that they want to evaluate it further in the summer of 2001. This further evaluation will include as many as 8 BRICK CMSs.