What term refers to the maximum number of vehicles that can reasonably pass over a given section of roadway in one hour?

The term that refers to the maximum number of vehicles that can reasonably pass over a given section of roadway in one hour is known as road capacity. Road capacity is a vital concept in traffic engineering and transportation planning, as it helps determine how effectively a roadway can accommodate traffic volumes. It takes into account the roadway's design, conditions, and various factors such as geometry, lane width, and traffic control measures.

Traffic flow, on the other hand, refers to the movement of vehicles along a roadway and is often expressed as a rate of passage per unit of time. While it relates to the dynamics of vehicles moving, it does not specifically represent the maximum potential of a roadway, which is captured by the concept of road capacity.

Vehicle count typically refers to the actual number of vehicles observed in a given time frame and does not imply the maximum capability of the road. Lastly, traffic density is a measure of how many vehicles occupy a specific length of road at a given time, which is different from measuring the maximum throughput of vehicles over time.

Thus, road capacity is the precise term used to identify the upper limit of vehicular passage over a roadway within an hour, making it the correct choice.