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To junction or not to junction

Posted: Fri Jan 18, 2013 6:07 pm
by ArlenBystander
In the case of a dual carriageway with a left turn segment that should not permit a u-turn, is it a good practice to not have a junction node between the turn segment(s) and the segments of the opposite direction of the carriageway?

For illustration purposes, here's a Permalink with the two turn segments highlighted. All turns are properly restricted to route correctly but would it be better/worse to eliminate the junction and have the segments cross without connecting?

The biggest problem I see would be a system generated error should someone actually make a u-turn but that isn't much different than the other problems that get reported when there is really no problem.

Thoughts?

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 6:13 pm
by AlanOfTheBerg
It is perfectly acceptable to have a single segment which does not junction with the other side of the road. Be sure and set the level to something different than the segment being "bypassed" in this manner.

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 7:29 pm
by AlanOfTheBerg
As it is now, using a slight angle results in only a "stay to the left" instead of a turn instruction. You can make your turn segment actually closer to the real turning location and make it near 90-degrees so the driver gets a "turn left." The driver should get at least two warnings about "turning left" so getting into a turn lane should be obvious to any competent driver. No need to create turn lanes, IMO.

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 8:36 pm
by AlanOfTheBerg
jasonh300 wrote:https://www.waze.com/editor/?zoom=7&lat ... TTTFTTTTFT

This is a good example of one that works and gives a Turn Left instruction from either direction.
Oooh, pretties! :)

Does the southern end really give a "turn"? That angle looks pretty soft to me... :?:

Re: To junction or not to junction

Posted: Sat Jan 19, 2013 12:40 am
by Bigbear3764
Hey Joe, I cleaned that interchange up a little and gave the turns a kick to force the turn left instruction. I don't like these turn lanes either, another one of those I found that was done before I started, so I left it. If I don't see error reports or complaints, I'll leave them alone. If the ballons pop up, then the mower comes out.

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 7:20 pm
by jasonh300
On those types of junctions with the crossed ramps (to prevent offramp to onramp routing), that's the only way I do it in Louisiana and Mississippi. By doing so, you eliminate the need for restricted turns in most cases. Less chance for something to be changed accidenally, and zero chance of routing against a restricted turn.

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 7:36 pm
by jasonh300
https://www.waze.com/editor/?zoom=7&lat ... TTTFTTTTFT

This is a good example of one that works and gives a Turn Left instruction from either direction.

Re: To junction or not to junction

Posted: Fri Jan 18, 2013 8:51 pm
by jasonh300
AlanOfTheBerg wrote:
jasonh300 wrote:https://www.waze.com/editor/?zoom=7&lat ... TTTFTTTTFT

This is a good example of one that works and gives a Turn Left instruction from either direction.
Oooh, pretties! :)

Does the southern end really give a "turn"? That angle looks pretty soft to me... :?:
Oops..no it didn't. I probably did that one before I figured that out. It will now.