User:PesachZ/Toll roads

From Wazeopedia

Waze has the ability to flag toll roads, to assist in providing better information and routing options to users.

Toll road effects

There are two effect of flagging a road on the map as containing a toll:

  1. Routes that traverse that segment will show a toll icon on the preview screen to alert drivers that this route will include tolls.
  2. When the client option to avoid tolls is enabled, a routing penalty is added to the route every single segment along the route marked a toll.
    • This means that any segment with a toll flag will be avoided if at all reasonably possible.
      NOTE: The toll penalty is very high, and the definition here of reasonable may seem extreme. The routing engine will prefer a significant detour to avoid a toll, but not one it considers to be insane or impossible. The exact threshold of the routing engines "insanity check" is proprietary information, and not published by Waze.
    • This also means that given two route options the routing engine will choose the one with the fewest number of tolled segments, regardless of if they are consecutive or not.

Which segments should be flagged as toll

The configuration used is designed to work well when a route must, or a driver chooses to use (a portion of) the toll road, and they have the avoid tolls option enabled.

Every segment (entrance/exit/hwy) which actually traverses through a toll booth, collection point, or ticket dispenser is marked as toll per current wiki guideline. This means that no matter what path you take to get through the tool location you only traverse a single toll segment per toll location, and are only assessed with a single toll penalty. This may mean that only a single segment is tolled, or if there are parallel segments going through the toll location (eg E & W ramps, a single segment of each path is tolled).

Benefits of using this method

There are a few benefits to this overall method of applying the toll flag, as opposed to the old method of marking every segment of a tolled road with the flag.

  • It allows the routing engine to pick a route with fewest numbers of tolls along the route.
  • It will apply an identical penalty to two different tolled roads (assuming they both have one toll collection point) regardless of how many segments the tolled road is made of. This allows two tolled bridges and/or tunnels to the same destination to be treated equally, and allow the routing engine to pick the most appropriate one for your route regardless of their individual segment count.
  • It will simultaneously solve the "I was routed through the rest area" URs since the hwy segments parallel to the rest areas won't be tolled and penalized anymore, therefore the rest areas will stop being favored.

Incremental toll roads

An added variation which should hopefully be added to the wiki, accommodates incremental toll roads which charge a toll based on the distance you travelled on the toll road. On such roads you are essentially being charged an incremental toll per interchange, or specified distance that you drive past. In this case we want the toll penalties applied to your route to match the number of toll increments you will pay. This encourages the routing to take you off the toll road as soon as reasonable, preventing additional toll increments, without having to toll each segment.

So to add those incremental penalties at a diamond interchange flag the segment between the off and on ramps as tolled, this method ensures any driver going through the interchange can only traverse one of the toll segments (the exit, the entrance, or the hwy continuation) as they drive through the interchange.

Theoretically this could have been accomplished the same task with only putting two tolls, in one of two configurations:

  • Combining the continuation, and the exit toll. However that would be deviating from wiki guidance to toll the segment that goes through the toll collection point (on the exit ramp).
    1. The segment before the exit, which would do double-duty and cover vehicles continuing or exiting.
    2. The entrance ramp at the booth.
  • Combining the continuation, and the entrance toll. However that would be deviating from wiki guidance to toll the segment that goes through the toll collection point (on the entrance ramp).
    1. The segment after the entrance, which would do double-duty and cover vehicles continuing or entering.
    2. The exit ramp at the booth.

Why should the exiting segment have a toll flag

In most cases the same results could be achieved by only marking the segments entering the toll area with the toll flag. This proposal recommends to flag the entering and exiting segments on incremental toll roads for increased simplicity in the guideline, and a few edge case benefits.

In an attempt to keep the guideline simple it endeavors to follow the current wiki guidance, which is super simple "toll only segments which actually traverse the collection (or ticket) point".

Then a modifier is added, "If it is an incremental toll road, also toll one segment of the road continuation between the exit, and entrance ramps at an interchange to provide an increased penalty for continuing along the toll road. If the only way to mark a toll on the road continuation will also affect exiting vehicles (e.g. a cloverleaf design), then do not mark the toll segment on the exit ramp to avoid assessing a double penalty to exiting vehicles."

This method is also more versatile for example it can be applied without modification to a road which is only tolled from certain approaches. since we are not tolling the road itself, rather the actual collection points on the approaches, we can accurately represent the setup without needing further exceptions to the rule

The reason we toll the exit segment as well is:

  1. To keep it simple "every toll collection point",
  2. To equalize the penalty for continuing on the toll road vs. exiting,
    This enables proper penalty configuration when several interchange in middle of a toll road for example don't have a toll applied (the NY Thwy has this in a section for 3 interchanges).