Rules of the Road: Freeway merging speed is about judgment, not just numbers
Q: Can you please remind drivers that when entering or exiting the freeway they’re supposed to get on at the speed limit, and stay at the speed limit until they’re fully onto the exit ramp?
A: Have you ever assumed someone was on your side, given them a podium to share their views, and then too late realized you weren’t as aligned as you thought? I think that’s about to happen right now.
While I agree with your underlying sentiment, the way you’ve framed that question implies that the speed limit is a minimum, not a maximum. Nowhere in the law will you find a requirement to reach the posted speed limit before entering a freeway, or to maintain that speed until you’re on the exit ramp.
We think of speed limits as the big numbers on black-and-white signs, but that’s sort of secondary to the law. The “basic rule” as it’s called in the law, states that “No person shall drive a vehicle on a highway at a speed greater than is reasonable and prudent under the conditions and having regard to the actual and potential hazards then existing.”
We start with a fundamental premise of being reasonable based on the circumstances. The law then adds some numbers — 25 mph on city streets, 50 mph on county roads, and 60 mph on state highways. (Other laws allow for changes to those numbers.) Speed limit signs are like the law telling anyone wondering where the line is for “reasonable,” here it is. That doesn’t mean every speed below it is automatically okay. Sometimes we encounter “actual and potential hazards” that demand slower speeds for safety.
There’s one other point in the law that’s relevant here. It requires drivers to “drive at an appropriate reduced speed” in a half-dozen or so situations. One of those is when approaching and going around a curve.
If I were to name a common characteristic of on- and off-ramps, it’s curves. Some ramps have long straight sections that leave room to speed up or slow down, but not always. The design of the ramp and the kind of vehicle being driven will factor into merging and exiting speeds.
Instead of expecting drivers to always reach the speed limit before getting on the freeway, it’s more reasonable to expect that sometimes they won’t. We should be looking far enough ahead to anticipate a merging or exiting driver, and be willing to slow down as needed (and as the law requires) to avoid a crash.
As you might have gathered by now, I don’t think our ability to drive at the posted speed limit is some sacred right. It should be thought of as a speed we can travel under ideal conditions, knowing that we often don’t have ideal conditions and will need to adjust.
But there is such thing as going too slow on the freeway. The law describes the minimum speed as one that doesn’t “impede the normal and reasonable movement of traffic except when reduced speed is necessary for safe operation or in compliance with law.” It gives transportation authorities the ability to post a minimum speed limit on a road when evidence indicates a need for it. But even without a sign, there is some point when merging too slowly and braking too aggressively when exiting becomes a hazard. Even if you don’t reach the posted speed limit, you should be going fast enough to smoothly merge with traffic. It’ll make it easier for you to find a gap, and safer for everyone around you.
This story was originally published April 20, 2026 at 5:00 AM with the headline "Rules of the Road: Freeway merging speed is about judgment, not just numbers."
