Urban planners and traffic engineers have many strategies for traffic calming, including narrowed roads and speed humps. Such measures are common in Australia and Europe (especially Northern Europe), but less so in North America, where the focus is often more on facilitating motorized traffic flow.
Speed bumps are lazy traffic calming. They do have specific uses, but too many engineers have applied them in a “when all you have is a hammer…” manner, even when the street would have been better served with lane narrowing, chicanes, or even the addition of trees.
Everything you just said is illegal on an open 4 lane highway in the USA. You can’t just narrow down a 4 lane to a 2 lane, then open it back up to a 4 lane later because it’s ‘convenient’.
A 4 lane is and stays a 4 lane, through and through the state.
Said highway also runs beside a major international airport, so they damn sure ain’t about to fuck with that…
By “lane narrowing” I meant reducing the width of the lane (e.g. from 12’ to 11’ or even 10’). Road diets (going from 4 lanes to 2 or 3) are a separate issue, although they can have traffic calming effects.
Also illegal in this state, you can’t just change the width of lanes…
Meanwhile I’ve never heard of speed bumps being implemented on a street wider than two lanes, so it sounds like your state’s DOT has some policy updating to do.
I am actually referring to back around 2012, when the DOT plus the IAB got a clue and started growing a few braincells…