|Feature : Frontage road|
|A minor road running parallel to a higher-speed more major road.|
A frontage road (also access road, service road, parallel road, etc.) is a minor road running parallel to a higher-speed more major road, often in an urban setting. The frontage road is connected at some points with the major road. A frontage road is frequently used to provide access to private driveways, shops, houses, industries or farms. Functionally, they usually behave as collector roads for local traffic along the sides of the highway. A frontage road is often, but not always, a one-way road.
How to tag?
Do not use the highway=*_link tag for the frontage road. Simply use one of the normal highway=* tags. As the frontage road is less important than the major road, it must also have a lower highway=* tag than the major road – regularly highway=residential. Example: If the major road is “tertiary”, then the frontage road is neither
“tertiary” nor “tertiary_link”. It has a lower type: can be “unclassified”, “residential”…
If the frontage road runs parallel to a surface street (as opposed to a highway=motorway or expressway=yes), it is actually a frontage lane that can be tagged with side_road=yes to help distinguish it from the main road. This is especially helpful if for some reason it is not possible to assign a lower highway=* value (e.g. because the frontage road is needed to connect to other important roads and therefore not less important), to keep routers from misleadingly alternate back and forth between the frontage road and main road.
To understand the difference between a frontage road and a frontage lane, see these examples.