Instead you pay a lot more in vehicle maintenance, and you make bicycling extremely uncomfortable forcing more people into vehicles.

That's the case for most traffic calming, isn't it?

No? Most traffic calming is not designed to send sudden shocks through your vehicle that cause extra wear and tear.

Wikipedia says

> Speed bumps (also called traffic thresholds, speed breakers or sleeping policemen) are a class of traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions

It's just a difference of degree of deflection.

1. they are being phased out in many locations because of that issue

2. there are many other types of traffic calming devices: https://en.wikipedia.org/wiki/Traffic_calming#Measures

1. Potholes are also being phased out in many locations, but apparently not on El Camino.

2. Horizontal deflection and blocking access (usually requiring more distance to be covered) both increase maintenance on vehicles; by my count, three out of four categories of traffic calming increase maintenance on vehicles --- it's clearly an allowed part of the design. Going back several comments, blocking access often makes cycling much worse too. As can narrowing, depending on how its done.

The vast majority of measures on the list I linked do not increase maintenance at all, and certainly don't cause a "lot more in vehicle maintenance". Some, like a roundabout, may cause driver to spend less in maintenance vs. alternative intersection designs.

How do you want to count? By category, I see 3 out of 4 categories that increase vehicle maintenance costs; some more than others.

By individual items: there's 6 items in narrowing, which I think is reasonable to say don't increase maintenance. There's 8 vertical deflections, which are all increasing. There's three in horizontal deflection, I'll give you roundabouts (I've argued enough about those elsewhere), so that's 2 more increasing and 1 not. For blocking, there's four, all of which are likely to increase travel distance.

So 6 + 1 = 7 vs 8 + 2 + 4 = 14. 7 out of 21 is the vast majority?

Pot holes clearly fit under vertical and horizontal deflection. Possibly block or restrict access. Deferred maintenance could be a general category of traffic calming.

Gentle vertical and horizontal deflections do not put undue wear on a car. This is why it is okay for roads to have things like turns. When cars go around roundabouts, through residential chicanes, or over properly designed speed humps at reasonable speeds, it does not put any more wear on a car than normal road features.

What kube-system said, but also:

Speed bumps are relatively gradual changes in height relative to pot holes. A properly built speed bump driven over at an appropriate speed doesn't "shock" your vehicle.

Speed bumps and roundabouts do not “wear out” your car. Not how you ever arrived at that idea.

That's an awful way to think about that.