Highways: Hard shoulder / emergency lane

[originalfoo]

In mod options, there's a setting to make Heavy trucks prefer outer lanes on highways.

However, many highways will have an outside lane that's used as an emergency 'hard shoulder' (eg. where broken down cars try and get to so they're not blocking traffic while they wait for service van).

Would it be possible to add an additional option (Policies tab in mod settings), something like:

--[ ] Outermost highway lanes are emergency lanes

The effect would be to restrict all but emergency traffic (police/ambulance/fire/disaster) from using the outermost lane via 'virtual vehicle restrictions' (in much the same way that the Ban private cars and trucks on bus lanes option does.

Doing it this way would allow users to optionally allow vehicles back on to outermost lane for some highways, eg. those that don't have an emergency lane.

One problem might be what happens if user doesn't have TM:PE installed but uses a highway asset that has hard shoulder? I was thinking if the hard shoulder was a bus lane in the road asset, that users without TM:PE would get an "almost hard shoulder" (busses, taxis, etc, would still use it, but it would be mostly clear of traffic).

What do you think?

[krzychu124]

I am not sure if I understand what you want to do 😕 . Do you want to somehow unlock these currently disabled outer lanes and restrict usage to all but emergency vehicles? I am thinking about 3 lane highway and its white continuous lines on both sides. Could you add some images with roads with that 'hard shoulder'?

[originalfoo]

First, to clarify what I mean by emergency hard shoulder: https://en.wikipedia.org/wiki/Shoulder_(road)

Example from England:

Note: 'Central reservation' lane is often omitted (it's usually found near junctions); but the outer 'hard shoulder' is almost always present on UK highways.

In England they are sometimes given a red texture (especially on older highways):

In Ireland they usually have a solid yellow line:

The wikipedia article above shows other examples.

Next comment will explain how option would work...

[originalfoo]

With new Outer highway lane is emergency lane option selected:

• The existing outer lane of the highway gets vehicle restricted to police/ambulance/fire/disaster.
• The lane next to it (eg. on a 3 lane highway, the middle lane) would then be treated as the 'outer lane' for traffic

In other words, that three lane high way becomes: 1 lane for emergency + 2 lane for traffic

This would allow any highway with 2+ lanes to be given an emergency hard shoulder, simply by treating the existing outside lane as emergency lane, and then the adjacent lane becomes the normal outside lane from perspective of normal traffic.

Players can of course paint their own solid lines, or whatever, to make it more visually real.

[originalfoo]

The outer lane is converted to emergency lane by adding virtual vehicle restrictions

It's same approach as the Ban private cars and trucks on bus lanes option; only in this case it's detecting outermost vehicle lane and restricting so that only emergency vehicles can use it.

[originalfoo]

Asset authors, who want to produce assets which take advantage of the new option, but also want to make it 'kind of work' for players without TM:PE, could optionally designate their outer lane as a bus lane (like normal roads can have bus lanes, only this would be a bus lane on a highway).

While not perfect, players without TMPE would see far less traffic on the outer lane due to it being flagged as a bus lane.

However, players with TMPE will get the full 'emergency lane experience' via the new option (the new option doesn't care whether the outer lane is a bus lane or normal road lane).

[originalfoo]

Note: Without the option, players could just manually vehicle restrict their existing outside lane to emergency vehicles, but it would be tedious.

And it would likely conflict with the Heavy trucks prefer outer lanes on highways option (because now heavy trucks wouldn't be able to use the outside lane).

Also it would add lots of data to save games which can already be problematic due to VictorPhilipp/Cities-Skylines-Traffic-Manager-President-Edition#160

With the dedicated option, players get a nice way to quickly give their highways a hard shoulder. There are some other benefits, for example if there is single lane ramp joining a highway, it would need lane connecting to both outside lanes (the hard shoulder and the 'normal traffic' outside lane), and the heavy trucks would know which 'outside lane' they should prefer.

Hope that clarifies everything.

[krzychu124]

Yup, now I understand everything, thank you for your explanation 😉

[originalfoo]

Closing this as it's now tracked by #515