American Institute of Certified Planners (AICP) Practice Exam

Which Level of Service is characterized by slow movement and frequent stoppages during peak traffic hours?

1. Level of Service D

2. Level of Service E

3. Level of Service F

4. Level of Service A

The correct answer is: Level of Service E

Level of Service E is characterized by slow movement and frequent stoppages during peak traffic hours. This level typically represents a situation where the volume of traffic is approaching the capacity of the roadway, leading to congestion. Under these conditions, vehicles experience delays, and the overall flow of traffic is significantly hindered. At Level of Service E, traffic conditions are often critical, meaning that the roadways are heavily utilized. Drivers may encounter significant delays due to the convergence of demand exceeding what the road can accommodate comfortably. This makes Level of Service E an important indicator for planners and traffic engineers when assessing roadway performance and planning interventions to improve traffic flow. In contrast, the other levels of service provide different traffic conditions. For instance, Level of Service A indicates free-flowing conditions with minimal delays, whereas Level of Service F describes forced or breakdown flow with extreme congestion—beyond what is seen at Level of Service E. Understanding these distinctions helps planners develop strategies that enhance traffic movement and reduce congestion during peak periods.