Avoid using blank messages including dashes for travel time applications as drivers may not understand these signs or assume they are broken. For applications that provide comparative travel times, a majority of participants preferred a display that provided both travel times and toll amounts on one sign.

Beware that deploying hybrid static-dynamic signs for traveler information is useful to drivers, but may encourage speeding.

• Countdown signs have potential to encourage speeding as drivers attempt to beat the time on the sign.
• Participants are more likely to slow down when automated speed control messages display their would-be fine instead of their speed.
• Participants indicated that with advisory speed progression applications it can sometimes be difficult to differentiate between the advisory speed sign and the posted speed limit sign.