The illustration above imagines you are at home and want to get to dinner at a lovely establishment in your nearby. How does the street layout affect your (yellow) paths to dinner?
A street system is the pattern in which a city’s streets are laid out. This pattern can have a big effect on how it feels to move around in a city.
Two types are discuessed here: grid system, in which streets are laid out in regular (grid) pattern (excetpions here and there allowed); and an artery system, often found in suburbs, in which many roads branch off of one main road.
Grid systems work well in cities for many reasons.
_They allow for multiple routes to a destination. This means if one route is blocked you still have many ways to get where you’re going. In an artery system if something happens on the main “artery” road, everyone is stopped, without a plan B, C or D.
_ Because the pattern is regular it also predictible. This makes navigating the city easier. If something is 6 blocks away, you’ll have a sense of that distance.
_The many intersections created by a grid system means that cars will be stopping more often and driving slower in between stops. This keeps speed in central cities lower, making it a safer place for pedestrians and cyclists.
_Gridded streets create blocks which give a rhythm to a journey. If done at the right scale, this rhythm can make a trip feel shorter than it actually is, which in turn promotes trips on foot or bike. Trips on foot and bike promote health!
_Because the grid gives everyone multiple ways to get where they are going, traffic is more efficiently dispersed amongst many streets. In a suburban artery system everyone has to take the same main road no matter where they are going so traffic can really back up.
The closer a car’s speed is to your walking speed, the less likely you are to die when one meets the other.
In fact, your odds of dying shrink from 85% to just 5% when a car slows from 40 mph to 20 mph. This is why the 20mph Zone inside cities movement is growing.
Scaling for All
Streets are safer when they’re treated as a right for all modes of transit, not just auto traffic. Many European cities have implemented laws to create these environments called Home Zone, Living Streets, Shared Space and Woonerf.
Drivers drive faster on wider and multi-lane roads, regardless of speed limit. The predicability of the open road often leads to passive driving. In some cities, signs are removed, lanes are narrowed or even curved to force drivers to slow down and be more aware of their environment.
In urban areas with a dense street network, drivers often must drive slower because of the narrower lanes, inherit unpredictability of active streets and short block lengths.