Understanding how different VMS messaging impacts driver behaviour.
This case study uses Compass custom services.
Variable messaging signs (VMS) is a method of alerting drivers of changing driving conditions. They can also be used to communicate non-traffic related messages. Transport professionals mostly use VMS for road safety interventions.
An experiment was done to see how messages can affect driver behaviour. By using Compass custom services, comparisons were made between different types of signs. The example below compares the effectiveness of “crash ahead” and “breakdown ahead” on a specific motorway. In this analysis, data were obtained for an hour before, during, and after sign activation.
Focusing on speed, the results for “breakdown ahead” found there was not much difference before, during, and after sign activation. With the plot graph, most of the dots are seen to stay close to the 100 km/h speed range.
With “crash ahead”, the average speed lowers during the time of the sign’s activation dramatically - almost 20 km/h lower than before the sign was activated. In the plot graph, the points of data aren’t as concentrated in one area compared to “breakdown ahead” and has more cars travelling slower than 50 km/h.
Results showed that “crash ahead” was more effective in changing driver behaviour. The experiment shows that particular words can positively change driver behaviour. Analysis and studies of what words affect drivers most could help shape the messages used on signs to further enhance road safety.