What are the two main ways in which drivers select a travel speed?

Drivers primarily select a travel speed through two main methods: perceptual cues and road message cues.

Perceptual cues involve the sensory information that drivers obtain from their environment, such as visual aspects like the width of the road, the presence of obstacles, and the behavior of other vehicles. These cues help drivers assess their surroundings and make quick decisions about their speed. For instance, a narrow road might encourage a driver to slow down due to perceived risks.

Road message cues consist of information provided by the roadway itself, such as speed limit signs, traffic signals, and road markings. These cues are critical as they communicate the legal speed limits and other regulations, and adherence to these messages is essential for safe driving.

Together, these elements guide drivers in establishing an appropriate speed, helping to ensure their safety and the safety of others on the road.