What is generally true about the flow of traffic on a freeway?

The statement regarding traffic flow on a freeway being continuous and uninterrupted is correct because freeways are designed specifically to facilitate high-speed vehicular traffic. Unlike surface streets, freeways have limited access points and are constructed without intersections, which allows vehicles to maintain a steady flow of traffic without the frequent stops that can occur on city streets. This design minimizes interruptions from traffic signals or stop signs, enabling vehicles to travel at higher speeds over long distances.

In contrast, other factors contribute to the inaccuracy of the other choices. For instance, traffic signals are commonly present in urban settings and residential roads but are not a feature of freeway design. Thus, the option suggesting that traffic flow is frequently interrupted by signals is not applicable to freeways. While some residential roads may facilitate slower speeds due to their nature and density, the continuous design of freeways supports a faster pace of travel. Moreover, although heavy trucks can be part of freeway traffic, they do not constitute the primary traffic flow, which typically includes a significant number of passenger vehicles traveling at high speeds.