Final answer:
The right lane on a three-lane straight road is typically reserved for slower-moving traffic, those intending to exit the roadway.
Step-by-step explanation:
In the context of roadway design and traffic laws, the right lane on a road with three through (straight) lanes is typically used for slower-moving traffic or for vehicles intending to make right-hand turns. In many regions, rules of the road encourage drivers to use the left lane for passing or overtaking slower vehicles.
Meanwhile, the rightmost lane is often for those driving more slowly, preparing to exit the road, or for commercial vehicles which may be restricted from using the leftmost lane. For example, on a freeway, the right lane would be the place for drivers who are trying to merge onto or off the freeway.
In city traffic, this lane is also commonly used to make right turns into side streets or parking lots. It is best practice for safety and traffic flow that drivers maintain awareness of their intended route and choose the appropriate lane accordingly.