Why Police Don't Enforce Speed Limits Strictly: An In-Depth Analysis

It's a common belief that police force does not strictly enforce the posted speed limits. However, there are several valid reasons why this is the case. This article delves into these reasons and explains why the enforcement of speed limits can be more nuanced than it appears.

Measurement and Probable Cause

The primary issue with strict enforcement of speed limits is the requirement for probable cause or reasonable articulable suspicion. To measure whether a driver has exceeded the speed limit, police officers often rely on various methods, including visual estimation, radar, and LIDAR.

Visual Estimation

Visual estimation is the most common method used, but it is highly subjective. In areas where the speed limit is set at 20 mph slower than what is safe, visual estimation becomes unreliable. Certified and experienced officers are trained to use visual estimation with a tolerance of ±5 mph. However, in my state, courts only accept visual estimation as probable cause if the speed involved is wildly different from the posted speed, such as 50 mph in a 25 mph zone. Stopping a driver for going 26 mph in a 25 mph zone is not supported by probable cause and is highly unethical.

Radar and LIDAR

Officers who are trained and certified in the use of radar and LIDAR typically have a tolerance of ±1 mph. This accuracy is crucial, but it still leaves room for detailed measurements that are required for courts to accept the evidence.

Discretion and Expediency

Even with strict measurements, discretion plays a significant role in traffic enforcement. Officers may decide to give drivers a 5 or 10 mph buffer, which can drastically affect how speed limits are enforced.

Speed Limit Setting and Traffic Engineering

Speed limits are not set arbitrarily. Traffic engineers follow specific guidelines to determine the appropriate speed. This involves collecting data on the actual speeds of vehicles on the road and considering other factors. Many states require that the road's speed limit be set just above or below the mean speeds based on a sliding scale, which is meant to prevent jurisdictions from setting dangerously low limits for revenue generation.

Validity of Speed Limits

Unfortunately, the validity of speed limits is often undermined:

Police administrators may increase patrols in areas where a speed limit survey is being conducted, skewing the results. Some politicians or bureaucrats may set speed limits by fiat, without a proper traffic survey.

Officers faced with a speed limit that is not supported by a valid traffic survey would be unethical in enforcing it. Fortunately, the public can now verify the existence of a valid survey through online resources.

Responding to Non-Emergency Calls

Lastly, officers are more likely to focus on emergency calls for service, which naturally results in a lower priority for routine traffic violations.

In conclusion, while the idea of strict speed limit enforcement may seem ideal, the realities of measurement, officer discretion, and the complex nature of speed limit setting make it a more nuanced issue. Understanding these factors can help dispel misconceptions and foster a better relationship between the public and law enforcement.