One-way streets are designed to improve traffic flow by

Answer: C — Allowing higher traffic capacity with fewer crossing conflicts

One-way streets boost traffic flow by routing all vehicles in the same direction, which increases how many cars can move through a street and reduces conflicts with opposing traffic. With no opposing cars, intersections become safer and turning movements easier, so signals can be timed more efficiently and more vehicles pass through in sequence. This combination—higher capacity and fewer crossing conflicts—best captures why one-way streets improve flow. The other options don’t reflect this core effect: changing lanes or looping routes doesn’t inherently achieve the same safe, efficient throughput.