Many accidents, including fatal accidents, are the result of that lack of common sense amongst drivers…or a simple lack of awareness. You can’t legislate it…but transportation departments at all levels are often called upon or outright required to account for it, hence why a lot of them “err on the side of safety”, because they need to cover their tail.

It’s sad, and it’s not the way things should be done, but that’s what happens when you have stupid drivers, an overzealous government, and greedy lawyers…

It’s ironic that there are specs for left turn arrows, while at the same time a bridge falls down, killing 9? people.

Government at it’s best? or worst?

The trouble is that the guidelines for using the “hard left” arrow are maybe a little too overzealous. On one hand, having the red arrow definitely increases safety, and really doesn’t cost anything extra to install. On the other hand, it does increase delay and therefore fuel as well.

What works well when it’s busy may seem like overkill in the middle of the night. Most of the intersections don’t even warrant signals in the middle of the night (hence my support of the red/yellow night flash). But, until the flashing yellow arrow, there wasn’t a well-understood way to switch between the “hard left” and the yield-on-green based on the time of day.

The flashing yellow arrow solves that problem, and based on testing it was well-understood by drivers, more so than the “left turn yeild on green”. I understand that Michigan will be removing the flashing red arrow in favor of the flashing yellow. The flashing red arrow required a complete stop before making the left turn, which wasn’t very efficient.

Ed: I’d have to do more digging to check. Theoretically, those county and local projects that use state aid funding would have standards similar to the state highways. But if it was purely local funding used, it’s quite possible that the local municipality used their own guidelines.

In the wisdom of Minnesota, they make left turns ‘illegal’ by adding the ‘red left turn arrow’.

With the 35W/62 construction, it’s very frustrating at Nicollet and Diamond Lake Road. This now handles the traffic for 46th, 50th, and soon 60th. Why can’t we have delayed green on all four corners?

http://www.dot.state.mn.us/trafficeng/signaldesign/2006manual/02_Traffic%20Signal%20Phasing%20Operations.pdf

This is Chapter 2 of MnDOT’s Signal Design Manual, discussing signal phasing and operations. If you scroll down to page 2-4, it lists MnDOT’s criteria for determining if a “hard left arrow” (known in the engineering world as a “protected left”) is required, vice going with a “protected-permitted” signal (the 5-lens signal that has both the arrow and the green ball).

That being said, they are very different at their respective intersections with “East Point Douglas Rd” just two blocks east of US 61.
80th St has left turn arrows with the “green ball”
Jamaica,1 mile south, has the hard left turn arrows.

My question is, WHY!!!!! They’re the SAME road design carrying the SAME levels of traffic to the SAME freeway! They are even both set up to only allow cross traffic on East Point Douglas to take turns (separate stages for south-bound and north-bound) One has a Cub, the other a Rainbow. One has a Kohls, the other a Target. One has a Menards, the other (had) a Home Depot.

The point is, these traffic engineers really don’t have an over-riding formula, personal preference comes into play.