Which factor does NOT influence our ability to accurately assess speed?

The ability to accurately assess speed can be influenced by various factors, with road markings being a less critical factor compared to other elements. Road markings do provide guidelines for speed, such as speed limit signs and lane boundaries, but they do not fundamentally alter a driver's perception of their speed in the way that other factors can.

For instance, driving capability directly impacts how well an individual can gauge their speed based on experience, understanding of vehicle dynamics, and reaction to driving conditions. Vehicle capability also plays a significant role, as the design and performance characteristics of a vehicle can affect how speed is perceived and managed. Weather conditions further complicate speed perception through effects such as reduced visibility, slippery surfaces, or strong winds, all of which can lead to deviations in estimating speed accurately.

In summary, while road markings serve as a helpful tool for understanding speed limits and lane positioning, they do not directly impact a driver's ability to accurately assess their actual speed compared to the other described influences.