The most effective solution to speeding are narrow streets. People speed because they are under the impression that it's safe. Making the street narrower and decreasing sight lines (e.g. by adding trees) reliably causes people to slow down.

But wouldn't that also make the street more dangerous? Seems like there wouldn't be a net gain of safety.

Slower speeds have an outsized effect on safety. Consider that taking 20% off the velocity of the car takes 40% off the kinetic energy of the car, and between 20% and 40% off of the distance it takes for the car to come to a stop.

It makes the street seem more dangerous, which prompts drivers to slow down and be more cautious.

It only makes the streets more dangerous if people keep speeding.

You might be right, that was not included in the study that I've read. On the other hand narrow streets may create non-remediable capacity problems in the longer run. Also, recklessness also is not completely stopped by narrow streets and trees.

At least this is what I see from my window.

Part of the problem is you usually can't drive over them at or even close to the speed limit. Especially for vans. So you either get them slowing down (squeaky brakes) and then accelerating (clattery diesel), or they smash over the bump and you hear the undertray scraping the ground.

Most trucks and vans can take most speed bumps at the speed limit (which is usually 25 or less anywhere there's speed bumps in the first place) with no ill effects other than accelerated wear and tear if the driver is so inclined...

I've never seen a speed bump that I would want to hit anywhere near 25 mph. Even speed humps are more like 10 mph max.

>Unfortunately, cameras increase the ticketing, but not reduce the problem that much

That's likely a feature, not a bug.

See also: sin taxes.