User:Nzahn1/Best map editing practice

Alleys

Alleys provide both unique benefits and challenges to the mapping community. They are exist extensively in urban and suburban road networks, but aren't intended for widespread use. Ideally, an alley should only be available to those who live or work adjacent to the alley, those who service those addresses, and as a last resort in case of closures of the nearby standard roads.

Should I map alleys?

[Currently being discussed at Champ level]

As of April 2023, the recommendation is to map alleys as they exist on the ground. However, be sure to follow the precautions listed below when adding alleys. Adding alleys is not a high priority, but rather should be done as time allows. Adding alleys to the map has several tangible benefits:

• When alleys are left off the map, speed data from users driving on alleys may be assigned to other nearby roads, polluting the data and impacting routes and ETAs.
• Without alleys, users who use alleys to access their parking pads or garages will be snapped to nearby roads, and may receive inaccurate routes.
• Alleys can provide a "detour of last resort" when no other roads are available.
• Adding alleys to the map can help localities who are Waze partners, allowing them to collect important crowdsourced data about the maintenance and status of these roads including pot holes, debris blocking the road, emergent flooding, and the status of snow plowing or ice build-up.

Historically, alleys have had disprite treatments across various map editing regions and states, with some communities choosing to map them as  Parking Lot Roads  while other communities may have chosen to use the  Private Road  road type, and still other communities have chosen not to map unless absolutely necessary. At one point, there were even experiments to alternate between  PLR  and  PR  block to block, in an effort to prevent through routes.

In recent years, the routing behavior of the  Parking Lot Road  and  Private Road  road types has diverged slightly and as of April 2023, the recommendation is to use  Private Road  for alleys. This has several benefits:

• Most through routes are prevented, due to the inherent transition penalty for  Private Road  segments on the routing server.
• Routes crossing standard drivable segments may be discouraged because of slower real-time and average segments speeds due to turn delays at junctions.
• In case of a closure applied to nearby standard drivable road segments,  PR  alleys could be used as a last resort detour, due to the high, but surmountable transition penalty. An alley mapped with  PLR  segments would never be offered as a detour, and routing could fail altogether if there are no other options.

There are some precautions that should be taken when adding  PR  alleys to the map:

• Be sure to follow local guidance. Segment naming, speed limits, and other measures may vary depending on region/region/locality. Some areas may require additional routing measures to ensure compliance with laws and regulations or in response to routing issues. These measures may include adding prohibited turns or difficult turns to continue straight when crossing standard drivable segments.
• Check nearby destinations. When adding alleys to the map, ensure all nearby House Numbers are nudged and the entry point for Residential Point Places, and standard Places are accurately placed. If nearby destination stop points are not checked, routing errors can occur, sending users to the back of businesses or residences.
• Watch for existing PRs. If there are existing  PRs  used as gates of a private installation or as a driveway, double check that you aren't creating a routing issue bypassing the gate or creating a preferential pathway.
• Unmaintained alleys happen. If an alley has fallen into disrepair and is barely passable, consider marking it as  Off-road / Not-maintained , which will prevent routes unless absolutely necessary. Alleys that only exist on paper, and do not exist on the ground, should not be added to the map.