Why speed limits don’t make our highways safer

Speed limits are the most ignored law in America. Everyone knows it, everyone does it, and politicians pretend they don’t.

Yet despite near-universal noncompliance, speed limits keep trending upward. That sounds backward — but there’s a reason. And if we want safer, smarter roads, we need to be honest about how limits are set, why they fail, and what would actually fix them.

Speed limits aren’t broken because speed itself is dangerous. They’re broken because the system is disconnected from reality.

This isn’t about reckless driving. It’s about reality. America’s speed policy is built on outdated assumptions, inconsistent enforcement, and political fights that have little to do with safety. Dig into the data and one thing becomes clear: The current system isn’t working.

And no — an American Autobahn isn’t coming anytime soon.

The risk everyone ignores

Speed limits aren’t chosen on a whim. They’re usually based on the 85th percentile rule: Engineers measure how fast drivers already travel, and the speed that 85% stay under becomes the benchmark.

In theory, this reflects real-world behavior. In practice, when most drivers already exceed posted limits, every traffic study pushes numbers higher. It becomes a feedback loop: People speed, limits rise, people keep speeding. The result isn’t safer roads — it’s inconsistency, which is far more dangerous than speed alone.

Safety debates fixate on top speed, but the real danger is speed variability — the difference between how fast vehicles are moving relative to each other.

A road where some drivers do 55 mph and others do 80 mph is dangerous not because of the fastest car, but because of the difference. High variability leads to congestion, abrupt lane changes, tailgating, and road rage. Uniform speeds are far safer. America fails here because limits don’t match behavior, enforcement is sporadic, and real-world speeds vary wildly.

Unsafe at any speed

Some argue we should simply raise limits to match reality. But the data doesn’t support that.

Outdated limits do breed distrust, but raising limits without fixing enforcement, road design, and driver training only widens speed differences. There’s also a political ceiling: Higher limits face resistance that has little to do with safety.

Insurance companies have long resisted higher limits. Greater speeds can mean more severe crashes, higher payouts, and larger claims — so insurers lobby accordingly.

Then there’s Vision Zero and its “safety over speed” movement, which prioritizes lower limits, stricter enforcement, and speed cameras to reduce fatalities. Critics argue it oversimplifies the problem by blaming speed while ignoring poor infrastructure, distracted driving, and inconsistent enforcement. The result is a political stalemate divorced from what actually works.

Why we can’t drive 55 ... or 85

The Autobahn always comes up in these debates, and for good reason. It works because everything aligns.

German driver training is rigorous, emphasizing lane discipline and high-speed control. Left lanes are strictly for passing. Roads are engineered for sustained speed. Enforcement is consistent and focused on the right behaviors — tailgating, lane blocking, and distraction.

You can’t copy just one piece of that system and expect the same result.

The national 55 mph limit of the 1970s was widely ignored and eventually repealed. Safety gains were modest and short-lived, while frustration and economic costs were substantial. Arbitrary limits without public trust don’t last.

RELATED: Mandatory speed limiters for all new cars — will American drivers stand for it?

Vintage Images/Getty Images

Brake check

Do speed limits actually work?

Yes — but only when they align with road design, real driving behavior, consistent enforcement, competent driver training, and low speed variability. Right now, America misses on nearly all counts.

Speed limits aren’t broken because speed itself is dangerous. They’re broken because the system is disconnected from reality. The solution isn’t simply raising or lowering numbers — it’s aligning engineering, enforcement, training, and expectations.

America’s biggest problem isn’t speed. It’s inconsistency. Until that changes, noncompliance will continue — and so will preventable crashes. Smarter speed policy won’t come from politics. It will come from practical engineering, and that would save more lives than any number posted on a roadside sign.