dedicated turning lane policy

[kianzarrin]

fixes #1102 see #1102

A) I changed dedicated turning lanes behavior for bus lanes:

• mode 1: bus lanes are considered part of car lanes. (same as before)
  mode 2: bus lanes are treated differently (changed: they are given a forward arrow)

B) I added a builtIn mode to change default lane arrow values as opposed to forced values.

• add to crowdin
  

depends on #1096 (I merged it with #1096 because I wanted to test my code using hot reload),

[kianzarrin]

except for crowdin, this is ready for review.

[kvakvs]

Nice

[kianzarrin]

this is how it looks like with TTL

[kianzarrin]

All in all, I found a couple of caveats:

---

here it's better to have 2 right turns:

notes:

• this is not a problem with the "dedicated turning lane" policy.
• user can alt-click with the lane-arrow tool to fix it.

---

in these 2 cases, It's better two have an extra dedicated right turn:

notes:

• this is not a problem with the "dedicated turning lane" policy.
• user can alt-click with the lane-arrow tool to fix it.

---

here (dedicated turning lane policy) it's better to have two right turns.

• this is not a problem with the "auto-TLL"
• use can alt-click with the lane-arrow tool to fix it.

---

to fix the caveats with the Auto-TTL turning lanes I can do this:

if altBus:
    SeparateTurningLanes(car+bus lanes) // current code
    // add this code
    if car lanes >= turn directions:
        SeparateTurningLanes(car lanes alone)

to fix the last caveat (policy) I can do this:

if no right turn and has only one bus lane to the right:
    do not treat bus lanes differently.
else:
    proceed as normal.

[kianzarrin]

I should also test with roads where the inner most lane is a bus lane.

[kvakvs]

When you have not enough outgoing lanes on a T junction, it is a valid choice to have one lane going both left and right. The traffic will not cross each other but they might somehow get confused and prefer that lane over 1 direction lanes?

Here example: T junction where road has LEFT ONLY lane and LEFT+RIGHT lane, going onto motorway. It works. There is also a traffic light.

[kianzarrin]

@kvakvs one lane going both left and right

Sure but when the user activates dedicated turning lane policy, he probably wants dedicated turning lanes :)

[kianzarrin]

more bus roads (I added bus lane props):

the marked section in the image above might be debatable. but I think its good (at least good enough)

[kianzarrin]

If user activates the "ban cars on bus lanes" option there could be a bit of a problem (with or without dedicated turning lane policy)

but I think that should be outside of the scope of this review.

[kianzarrin]

and this is with timed traffic lights

I don't see any additional problems with the middle lanes.

[kianzarrin]

On the second though I am not so sure about this

if I do change these lanes to turning lanes, then the buses that want to go forward have to change multiple lanes to get to the forward lane.

[DaEgi01]

this is how it looks like with TTL

here are some "issues" where the lanes break at least my expectation.

that is ... if the bus lanes are supposed to be dedicated.
if not, forget my screen.