On an expressway, how are interstate and other limited access highways usually reached?

The correct answer is that interstate and other limited access highways are typically reached by an entrance ramp. Entrance ramps are designated roadways that lead vehicles directly onto the highway, allowing for a smooth transition from local roads to high-speed travel. These ramps are designed to facilitate safe and efficient merging onto the highway, with gradual inclines to match the speed of traffic already on the expressway.

Using entrance ramps helps maintain the flow of traffic and minimizes disruptions that could be caused by abrupt stops or turns, which would be the case with options such as making a U-turn or turning onto a side street. Additionally, parking lot access does not provide a means to directly enter an expressway, as it is intended for use by vehicles seeking to access specific establishments rather than merging onto high-speed roadways.