When a unit indicates a "high rate of speed," they are typically describing:

The term "high rate of speed" is used to describe a vehicle that is traveling significantly faster than the established speed limits for that area. This interpretation aligns with general traffic regulations where speeds above the limit indicate a violation of safety laws meant to protect all road users.

When someone refers to a vehicle as going at a "high rate of speed," it typically suggests that the vehicle poses an increased risk of accidents or other dangerous situations due to its excessive speed. This is especially relevant in law enforcement and highway patrol contexts, where officers need to assess and react to the behaviors of drivers on the road.

In this case, a vehicle in pursuit can reach high speeds, but that situation is more specific and context-driven. Similarly, a slow-moving vehicle or normal traffic speeds do not fit the essence of the phrase since they would not indicate a dangerous or problematic scenario. Thus, solely identifying a speeding vehicle is the most accurate interpretation of a "high rate of speed.”