22 July 2009

Accessibilty vs Mobility

Here is an article that discusses two concepts in transit:
Mobility = how fast can the system get you different places
Accessibility = How accessible are the places you want to go.

Many people automatically think transit should equal mobility. Think fast cars, fast trains connecting distant places. Mobility is a fine measure as far as it goes, but really what we want in our daily life is accessibility. And some forms of transit inherently change how cities operate and they therefore increase access.

For example. Train stops often are hubs of commercial activity where daily purchases can be made. Bus stops, not as much. Density hubs are essential to walkable urbanism.

When these hubs develop, many of the daily needs can be satisfied with short walk: to the convenience store, the coffee shop, a place for lunch with friends, and the two trips to school with the kids every day etc..., even if you still commute to work for example. Studies have shown that walkable urbanism reduces car trips by 40%. For example a household in Green Township may have start their car 8 times a day. But that same family living in an walkable urban area may only start their car 4-5 times. Food for thought.

Update:
Amory Lovins and the other authors of “Natural Capitalism” cited a study’s estimate that reinstating the corner grocer would by itself reduce gasoline consumption by 6%.

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