What is the primary benefit of medians on expressways?

The primary benefit of medians on expressways is that they separate opposing lanes of traffic. This effective division helps to prevent head-on collisions, which can be particularly dangerous and often fatal. By creating a physical barrier between vehicles traveling in opposite directions, medians enhance safety on high-speed roadways. This separation also allows drivers to have a clear understanding of their lane and traffic flow, contributing to reduced confusion and accidents.

The other options do not accurately represent the key function of medians on expressways. For instance, while some road designs may consider bicycle lanes, this is not a standard function of medians on expressways, which are typically focused on motor vehicle traffic. Similarly, while it is possible for expressways to have fewer exits due to their design, this is not the primary reason medians are implemented. Lastly, medians do not create additional driving lanes; instead, they focus on reducing risk by managing traffic flow and enhancing overall road safety.