Google Maps has a bicycle layer which shows three main types of bicycle facilities: off-road pathways (dark green), roads with bike lanes (lighter green), and roads that are preferred bicycle routes (dotted green).

As of this today, the city of Detroit has been updated.

• Milbank Greenway added
• Conner Creek Greenway added (including St. Jean and Clairpointe bike lanes)
• Southwest Detroit Greenlink added (bike lanes only)
• Atwater bike lanes added
• “bike lanes” on Joy Road removed
• “bike lanes” on Fort Street removed
• RiverWalk sections added

There are still more corrections to make.

• W. Outer Drive and W. Chicago are shown with bike lanes when they only have shoulders.
• There are still some sections of sidewalk shown as “preferred” bicycle routes.
• The Southwest Detroit Greenlink bike routes should be labelled as “preferred.”

We’ll get to these changes unless someone beats us to it.

We also removed the sidewalk along Lakeshore through the Pointes as a preferred bicycle path/trail.

What are the benefits?

For one, the map can help cyclists map their route. It’s interactive and up to date, though some may still prefer a printed bike map, especially since not everyone has a smart phone or direct access to the Internet.

Having an accurate bicycle layer also affects how Google generates bike route directions. Google will try to route cyclists on to bike lanes and preferred routes when it makes sense.

On the other hand, having an inaccurate bicycle layer can make bike directions less valuable. Google has directed us out of our way to use a sidewalk in Troy that has been labelled as a preferred bicycle route.

How to update the bicycle layer

The bicycle layer can be updated using the Google Mapmaker utility. There is a review and approval process for changes so it’s not as instant as Wikipedia.

Mapmaker gives you the ability to change roads attributes, sidewalks, places, and more. It appears bike racks are not being added to this map.

Guide to Mapmaker bicycle facilities

The Google guidelines on how to appropriately label bicycle facilities aren’t always that clear, but here are some key points.

• Paved shoulders are not bike lanes. Google’s best practices says, “Roads without explicit paint markings or signage indicating a bicycle lane should not be given the ‘On-street bicycle lane attribute'”. Since paved shoulders of adequate width can improve bicycling, they can be labeled as “preferred.”
• Sidewalks and sidepaths are not trails/paths. Sidewalks and sidepaths should be documented as part of the road attributes. Google’s best practices says they should only be mapped as separate trails/paths when they’re “separated by a river, railway, or other impassable physical barrier.” Yes, many parts of Oakland County has improperly labelled bicycle features.
• Sidewalks are rarely preferred bicycle routes. If the above guideline is followed, sidewalks along roads can’t be. It’s less clear for sidewalks that are not along a road. In some cities like Royal Oak, bicycling on a sidewalk is prohibited. Sidewalks aren’t usually not cleared of snow by cities unlike streets, so their value in the winter can be variable. We’ve removed a preferred sidewalk segment in Royal Oak that had stairs.

Tags: bike directions, bike lanes, Detroit, Google Mapmaker, Google Maps, safety paths, sidepath, sidewalk

This entry was posted on Wednesday, December 21st, 2011 at 7:12 pm and is filed under Detroit, On-road bicycling, Trails. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.