Roundabouts and Stop signs

[Imhotep]

I'm not sure whether roundabouts should have Stop signs at the entrance roads.

Theoretically, the cars that are already on the roundabout should have priority of way. One can set a road as a Priority road. Setting a roundabout as a Priority road means a stop sign is placed on the entrance roads.

However, having cars stopping at the entrances to roundabouts seems to go against the idea of free-flowing roundabouts.

Which way is better?

[andycishere]

Have you tried the TM:PE mod? That one provides you roundabout traffic rules or you can set them individually on crossings.

[Imhotep]

Originally posted by andycishere:

Have you tried the TM:PE mod? That one provides you roundabout traffic rules or you can set them individually on crossings.

No, I've not tried TM:PE yet.

[Dabulous]

I've found when building roundabouts, especially large ones, that it definitely improves traffic efficiency to have stop signs at the entrances. This gives vehicles within the roundabout right of way so that they can get through and out quickly. In any traffic congested area, prioritize getting traffic OUT over getting traffic in. The AI tries to change lanes so aggressively that having no stop signs causes traffic jams and fills up your roundabout with traffic.

Here is a large roundabout where I placed a ton of incinerators and recycling plants in the center. My garbage trucks get in and out fine and service a city of 150k, because I put stop signs only on the outer entrances of the traffic circle. Traffic in the circle flies through and out.
https://steamcommunity.com/sharedfiles/filedetails/?id=2706788386

[Imhotep]

Originally posted by Bobby:

I've found when building roundabouts, especially large ones, that it definitely improves traffic efficiency to have stop signs at the entrances. This gives vehicles within the roundabout right of way so that they can get through and out quickly. In any traffic congested area, prioritize getting traffic OUT over getting traffic in. The AI tries to change lanes so aggressively that having no stop signs causes traffic jams and fills up your roundabout with traffic.

I think it probably makes more sense to have roundabouts as priority roads.

I think I'll test it out on each of the roundabouts on my dumbell interchange.

[Dabulous]

Originally posted by Imhotep:

I think it probably makes more sense to have roundabouts as priority roads.

I think I'll test it out on each of the roundabouts on my dumbell interchange.

If you set a circular road as a priority road the game will automatically place stop since at all the entrances.

I prefer setting all my junctions manually, not just in traffic circles but everywhere. The game places too many traffic lights where there should be a through way with stop signs on the side roads. So, every time I build a new neighborhood I go through and toggle all the intersections to my preference as part of the process.

[MessengerOfRage]

Originally posted by Imhotep:

I think it probably makes more sense to have roundabouts as priority roads.

of course it does. without priority applied it's just a circular road.
a roundabout is defined by the rules applied.

[Imhotep]

Originally posted by Coookyman:

Originally posted by Imhotep:

I think it probably makes more sense to have roundabouts as priority roads.

of course it does. without priority applied it's just a circular road.
a roundabout is defined by the rules applied.

At low-to-medium traffic volume, a non-priority road roundabout - with two one-way lanes - looks to run smoother/better than a priority road one. Vehicles can drive onto the roundabout without making a stop, and they rarely get in the way of other traffic already on the roundabout.

It's probably at high traffic volume that the priority road would do better. Unfortunately, my road network is so well-designed that I'm not sure if I'll be able to test this. :)

[MessengerOfRage]

the problem comes with overload...
under heavy traffic: if you give incoming trafic priority over outgoing traffic = gridlock
traffic flows will block each other.
if outgoing traffic has priority things keep moving, if the overload was temporary it will clear itself over time.

[Imhotep]

Originally posted by Coookyman:

the problem comes with overload...
under heavy traffic: if you give incoming trafic priority over outgoing traffic = gridlock
traffic flows will block each other.
if outgoing traffic has priority things keep moving, if the overload was temporary it will clear itself over time.

I just watched a line of half a dozen cars approach an almost empty priority road roundabout. For a start, the stop at the roundabout started to create a traffic jam. Then as the first car entered the roundabout, the line advanced one and then they all stopped again. And so on. So the sixth vehicle stopped and started six times.

It seems to me that it might be better to keep roundabouts as non-priority roads, until such a point as the roundabout itself starts to congested, at which point to could be made a priority road.

[Great Sage Equal of Heaven]

Forget this 'priority road' stuff. Set give way signs on all the entrances to the roundabout.

Then get the TM:PE mod and ensure your lane arrows and intersection rules are all set correctly.

That mod is amazing, it's ruined vanilla skylines for me

[WhiteKnight77]

Originally posted by Nick:

Forget this 'priority road' stuff. Set give way signs on all the entrances to the roundabout.

Then get the TM:PE mod and ensure your lane arrows and intersection rules are all set correctly.

That mod is amazing, it's ruined vanilla skylines for me

Give Way = Yield Sign.