The correct choice highlights that there may be crosswinds when exiting tunnels. This phenomenon occurs due to changes in air pressure and the design of the tunnel structure itself. As vehicles pass through a tunnel and emerge back into an open area, the difference in environmental conditions can create wind shifts that may affect a vehicle's stability and handling. It's critical for drivers to be aware of this potential for crosswinds, as it can be particularly hazardous, especially for larger vehicles like trucks or buses that are more sensitive to wind forces.
While headlights are often required in tunnels for visibility and safety, the specifics can vary by location and are generally aimed at enhancing safety rather than a universal rule. Speed limits might not strictly enforce a maximum of 40 mph or less in all tunnels, as the limits depend on tunnel design, location, and traffic conditions. Finally, radio signals tend to weaken rather than strengthen inside tunnels due to the lack of signal reception and the shielding effect of the tunnel structure. Understanding these factors can help drivers prepare adequately for the unique driving conditions presented in tunnels.