Evaluation of Changeable Message Signs (CMS) on I-4 at Exits 30A and 30B to Assign Ramp Traffic and at Princeton St. to Sign for Cultural Events;Final rept

摘要

Florida Department of Transportation performed an experimental analysis of a series of changeable message signs functioning as freeway guide signs to assign traffic to Universal Theme Park via one of two eastbound exits based on traffic congestion at the first of the two exits. An examination of crashes along the entire route indicated a statistically significant increase in crashes at the first eastbound exit following the actuation of the system. Behavioral analysis scored from video tapes of driver behavior at the first eastbound exit, revealed that the reassignment of the theme park exit was associated with an increase in the percentage of motor vehicle conflicts such as the percentage of vehicles cutting across the exit gore and the percentage of motorists making unsafe lane changes in the immediate vicinity of the exit. A human factors analysis revealed that the method used for switching the designated or active theme park exit on the series of changeable message signs led to the presentation of conflicting messages to some motorists. The second experiment evaluated the use of a phased method of switching the designed theme park exit to eliminate the delivery of conflicting messages. The new method for switching the designated theme park exit was not associated with an increase in motorists cutting across the exit gore or unsafe lane changes. Based on the results obtained in the second experiment, it is recommended that the system used to assign the active exit based on traffic congestion be added to the MUTCD. A third experiment evaluated the use of a changeable message signs to provide information on cultural events in the Orlando area at a single exit. These signs were not associated with an increase in crashes. It is also recommended that this use for changeable message signs be added to the MUTCD.