Carpool, HOV, Transit lanes/Revision

From Wazeopedia

Carpool lanes, High-occupancy Vehicle (HOV) lanes, and Transit lanes are road lanes reserved for cars carrying more than the driver. The number of required passengers in the vehicle can vary depending on the specific road.

Although currently Waze does not support the requirements of routing over these types of lanes, there are plans to add support for them in the future.

How to map

As an interim measure, the following decision matrix should be used, unless your country/state has different guidance.

Configuration compared to standard lanes Minimal separation Significant separation
Restricted lane(s) with same configuration as standard lanes Never map (1a) Almost always map as Parking Lot Roads (1b)
Different configurations (e.g., limited exits) Usually not mapped (2a) Always map with same road type as regular lanes (2b)

Key/Notes: Minimal separation: Restricted lanes parallel regular lanes in either direction, with little separation (less than 10m, and perhaps less than 15m). Waze may not always be able to tell whether drivers are in the standard lane or restricted lane.

Significant separation: Restricted lane is almost always over 10m, preferably 15m, away from all standard lanes of traffic (both directions). Waze should be able to track which segment the driver is really on.

Same configuration: Restricted lane and standard lane both has access to the same interchanges. The route for either one is valid if the driver takes the other option (though Waze may choose to route them differently in some cases). All exits and entrances to the highway can connect to both sets of lanes at all times, without bypassing any section.

Different configuration: Any situation not covered by "same configuration." The restricted lane may bypass exits ("express lane"), or may connect to other bypasses routes not available from the standard lanes. Because of this, a route valid on the standard lanes may be impossible for a driver in the restricted lanes to follow, or vice versa. Signage may also conflict between the lanes, even where they are equivalent.

(1a) Never map, no advantages, all disadvantages. Drivers are getting the same route as they would without the special lane, except that they use a special lane. Waze will have difficulty reading GPS to determine which lane the driver is in, due to minimal separation.

(1b) While the route is the same (lanes do not bypass exits or otherwise substantially differ from standard lanes), it is OK to map these lanes. Waze can easily track the drive to the correct lane, since there is enough separation. However, they should be marked as Parking Lot Roads, so that Waze does not instruct drivers to take them inappropriately. Drivers who qualify for the lanes may enter them at will, and Waze will "reroute them" (no real change to route) correctly, with updated driving times based on their known speed properties.

(2a) Crowded with different configuration: Judgement call, but preference would be to not map this situation. That is because mapping them is only an advantage for those who ignore the Waze route and take the restricted lanes despite lacking the instructions to do so... whereas drivers who follow Waze instructions may sometimes get bad routes where Waze could not determine the correct lane; the driver is in the standard lane, and may have an appropriate exit that Waze skips because Waze "sees" the driver in the restricted lane that skips that exit. If the special lanes are mapped mapped, set each entrance segment as a PLR (tolled if HOT) with same suffixing as in (2b) below.

(2b) Spread out, with different configurations: Always map, and use the Freeway road type, even if the standard lanes are of a different type, assuming the restricted lanes have a limited access highway configuration. Use a road name suffix of (HOV) or (HOT) if appropriate. Set segment restrictions for HOV "vehicle type" if applicable. Do not use parking lot roads in any part of the map, including entrance lanes, as the penalties may prevent Waze from suggesting the special lane route where it is faster. There are no significant disadvantages to mapping this way, as Waze can track the well-separated traffic (see one concern in the "Important note" below). Were the special lanes left off the map, Waze might cause routing or reporting problems as follows. Routing issues: with a different configuration, drivers in these lanes do not have the same exit/interchange options as other drivers, and Waze may instruct the driver to take an exit that is not available. Mapping the lanes according to their special configuration solves this, as Waze notices the driver taking the lane. Reporting problems: Waze may issue Map Problem (MP) reports if the lanes were not mapped and the GPS tracks for the lanes are too far from the mapped standard lanes. Important note: Drivers who are not permitted to use the lanes may be routed by Waze via them, but it is up to the driver to obey traffic laws, and Waze will successfully re-route around them when the driver does not enter the special lane.

Future support

Supporting these lanes is a priority for Waze, and they are aware of the problems caused by such lanes.

A complete solution needs to consider the following factors:

  • The driver would need to tell the Waze client app how many passengers are present in the car for that trip. Waze would only offer routes over carpool lanes when there are sufficient passengers to be eligible
  • A new road type of "carpool lane" would be added with an entry for how many passengers and/or vehicle type (zero/low-emmission, mororcycle, etc) are required to use it
  • The ability to change the direction of the car pool lane automatically based on time of day and day of week. This is also necessary for other roads
  • The ability to set the minimum passenger count to zero (meaning the road is open to all drivers) based on time of day and day of week
  • As car pool lanes are often adjacent to normal roads, GPS tracking is not sufficient to differentiate the two. For accurate road speeds Waze needs to assume you are using the car pool lane when you have passengers (and/or based on your speed)
  • HOV lanes are being merged with Toll lanes (HOT lanes) and the user needs to be able to select if they want to allow toll roads. The map needs the ability to track multiple lane restrictions (HOV and/or Toll) for the same road rather than defining the road as either an HOV or a Toll lane.