- It's important to understand how we've built cities if we want to reform them into something better, to see how they can be gradually migrated to a better form of development
- Car-oriented development has been amazingly effective at spreading itself, trying to understand how it propagates and sets the stage for its success can be useful to conceive of how TOD can hopefully replace it
- To understand its pattern of replication so as to know when we are doing it, so we can avoid that trap
Basics of car-oriented development
- Residential areas
|These two images are from Swindon, UK - 85% car mode share|
|To scale, 9 houses in Japan (3 deep plus a street, 3 across) vs 3 houses in Vancouver, Canada|
Of course, if you want to avoid having cars everywhere, making areas ugly as sin, and don't want to use expensive underground garages, the density limit of parking requirements is even tighter.
Likewise, in consideration of the residents, there needs to be ways to force through traffic off of residential streets, often resulting in cul-de-sac and the like.
- Retail and job centers
- The catchment area
- The local traffic
- The capacity of the road network
- The road network
Street-based car-oriented developmentFirst, what does a car-oriented city based on regular streets look like?
Highway-oriented developmentHighway have a big impact on traffic and development patterns. Since they are much faster than regular streets, people often have an advantage to take detours by the highway instead of traveling slower on city streets. The result of highways is thus a concentration of traffic on the highway, drawing them away from arterials. Highway interchanges also become the most accessible places with the biggest catchment areas of the entire region:
|10-minute driving distance between an interchange versus an arterial far from highways|
- Opening the way for more sprawl
- Draining traffic off of existing commercial arterials
- Attracting commercial businesses and employment centers to highway exits
|An AEON mall in Obihiro, put inside a residential area, do not mistake it for a huge parking lot, it's just the parking on the roof that gives that impression|
|You can see the AEON sign in the background, with a 8-story residential building in the foreground|
|Another AEON mall marked by the red "F", in Asahikawa|
|What it looks like from the street|
Conclusion: how to avoid HOD and what we can learn from itHighway-oriented development is not just a form of development that favors cars, it is one that essentially punishes any other mode of travel. A street-based car-oriented development at least allows for other modes of travel to exist and even the possibility of conversion if need be. HOD has no redeeming features whatsoever for sustainability and multi-modality. To avoid it, there are two main solutions:
- Do not build any highways inside urbanized areas, or even high-speed arterials (what Charles Marohn at Strongtowns calls Stroads). Build highways so that they go around cities and do not penetrate them, with very few exits very spread apart, this will reduce the catchment area of highways and avoid them being used for local trips. Local car traffic should be dealt with by a tight grid of lower-speed arterials with frequent intersections (high capacity, low speed, low cost).
- Toll highways high amounts, 10-20 cents per km (15-30 cents per mile). This can be justified by the high cost of building and maintaining them. Tolling highways will significantly reduce demand for it, and commercial developers will want to avoid locations that require people take highways to access stores and job centers, because the tolls will be a constant irritant to potential customers.
As bad as it is for sustainability and as wasteful as it is, HOD is incredibly successful at imposing itself, so taking inspiration from it for TOD makes all the sense in the world.