Chapter 2: Speed Limits

Proper speed management is one of the most critical skills for any driver, as speed is the single greatest factor in determining the severity of a crash. Understanding and obeying speed laws is not just about avoiding a ticket; it is about having enough time to perceive, react, and stop for hazards, protecting yourself, your passengers, and everyone else on the road. This knowledge is essential for both the driver’s exam and for a lifetime of safe driving.

The Basic Speed Law

Colorado law operates on a fundamental principle known as the Basic Speed Law. This law requires that a person must never drive a vehicle at a speed greater than is reasonable and prudent under the conditions then existing. This means that even if a speed limit sign posts a higher speed, the driver is legally obligated to slow down for any hazard, such as bad weather, heavy traffic, poor visibility, or a winding road.

For example, on a rural interstate posted at 75 mph, driving at that speed during a blizzard or in dense fog would be a violation of the Basic Speed Law. The legal and safe speed is the one that is reasonable for the current circumstances. A police officer can cite a driver for driving too fast for conditions, even if they are traveling below the posted maximum limit. This principle underscores that the posted number is a maximum limit for ideal conditions only, not a mandatory speed.

Colorado Default Speed Limits

When no speed limit sign is posted, drivers must follow the statutory or “default” speed limits set by state law. These limits are based on the type of roadway and the general character of the surrounding area. Assuming a specific limit without seeing a sign can be a dangerous and costly mistake.