A 3-minute lesson from the Oregon course. Read the rules and examples, follow the handbook page references, and check your understanding before you move on.
A speed limit is the most you may drive in ideal conditions. Oregon's basic rule asks more of you: your speed must also fit the conditions right now. In rain, fog or heavy traffic, the legal speed can be well below the posted number.
Basic rule
You must drive at a speed that is reasonable and cautious for existing conditions. It applies on all roads at all times.
Digital variable speed signs use road, weather, traffic and visibility sensors to lower speeds when conditions require. They may also show the reason for the reduced speed.
If you drive slower than the normal speed of traffic, use the right lane or drive as close as possible to the right curb or edge, unless you're preparing to turn left.
The limit is 55 mph but dense fog cuts your view to a few car lengths. Driving 50 is under the limit yet can still violate the basic rule. Slow to a speed that lets you stop within the distance you can see.
Check your understanding
Read the question, decide on an answer, then open it to check the explanation. These are Roadwise study questions based on the source handbook.
Oregon's 'basic rule' law requires you to drive at a speed that is:
Always at the posted speed limit
As fast as safely possible
Within 5 mph of the flow of surrounding traffic
Reasonable for current conditions
Answer: Reasonable for current conditions
The basic rule requires a speed reasonable for current conditions.
