Mapping turns with a "turn curb"...

For this area, take a look at the imagery though the road configuration is accurate (From Garfield going into the service road to the Aztec Center):

First off, to remove any assumptions, this area is drive on right. So, coming from the east (going westbound into this intersection), it’s kind of clear that there is no left turn allowed due to the curb. There is actually a sign there that says right turn only, so it’s prudent to add a no-left turn restriction.

And it’s clear that going northbound that a right turn is allowed going east.

My question is that there is no sign saying “no left turn” southbound into this intersection. Despite this fact, that “turn curb” effectively makes it tough to make a left turn, forcing almost a u-turn to make this turn.

Question is, despite not having an explicit “no left turn” sign restricting this turn (southbound turning east):

  • should a turn restriction be added though there’s no legal restriction from doing so?
  • Or should the geometry of the turn lane be made such that the angle is almost like a u-turn ? What if there’s not enough runway to do so?

I see autorouting applications, including OSRM and Graph hopper, make a left turn on things that look like this, which I would think is improper. I’ve found from experimentation that making the angle very sharp will discourage this turn, and of course the no-left turn restriction works too.

Any suggestions? Thanks in advance!

The right turn only sign makes it effectively a no left turn.
So yes, you should add a turn restriction.