Great Residential Streets - Part 1

August 23, 2010 by Wes Edwards

As professionals involved in urban design part of our role is to make great streets, but what makes a street great and how can we ensure that residential streets are places that are good to live in? In this article I'll explore the concepts around suburban residential streets.

I'm sure that if we all made a list of our favourite residential streets there would be a huge variety of streets nominated and for various and perhaps conflicting reasons as there are a range of elements that help to make a street great. Some are tangible physical attributes such as the width of the street, the speed of the traffic, or the number of trees. Others are more subjective, relating to character and other less measurable concepts.

Within the variety of attributes there are probably some that most of us would agree on, and more importantly have some ability to manage, control or influence, particularly at the planning or design stage. Most would probably say that a liveable residential street is one with low traffic volume and low vehicle speed. A good residential area needs to have sufficient parking in some form or other. A liveable residential street is friendly to pedestrians and cyclists, and a good street is also a place with character - a nice place to be not just a movement thoroughfare. How do we as planners and designers build these things into our streets?

Traffic Volume
One of the easiest ways to classify streets is on the basis of volume - busy streets and quiet streets. All other things being equal I expect most people in suburbia would prefer to live on a quiet street with low traffic volumes. High traffic volumes are associated with noise, and we tend to have less community interaction on a busy street than on a quiet one due to the difficulties in crossing the road. Walking and cycling is less enjoyable on a busy road.

When designing residential areas it would be a good goal to maximise the number of quiet streets as much as possible. Clearly not all streets can have low traffic volumes, but by careful attention to the pattern of streets we can distribute and concentrate traffic to work towards this goal. A common solution to this problem has been the creation of cul de sacs, but as anyone familiar with new urbanism principles knows cul de sacs have fallen out of favour primarily due to their low connectivity deterring walking and cycling.

It would also be inappropriate to place a street along a route that would attract too much traffic - a "rat-run" route that provides a short-cut between two busy roads needs to be designed to handle the higher volume of traffic or avoided all together in favour of streets that don't provide for a shortcut.

As traffic volume increases the number of people in a hurry to go somewhere tends to increase and that brings us to the issue of speed.

Traffic Speed
As we all know high vehicle speeds don't provide the best residential environments. Walking and cycling are more attractive when vehicles are moving more slowly, and should a crash occur the severity of the crash is substantially reduced when vehicles are travelling slowly. The chances of a pedestrian surviving a collision with a vehicle increase from 60% at 50km/hr to 95% at 30 km/hr. Keeping traffic speed to 30 km/hr or below on residential streets is therefore a worthy goal.

The problem of managing vehicle speed on streets has generated a wide variety of potential solutions. In some cases, such as addressing speed problems on existing streets, the available engineering and design options are limited to devices such as speed humps, but with new streets there are more effective options available. In every case activating the street with more pedestrian and other activity will help to reduce speed and moderate driver behaviour.

For new streets there are three key principles that provide lower speeds. Each one can influence speed but they work best in combination.

I'll cover these principles in Part 2.

This is a reprint of an article I wrote that was published in the September 2009 issue of URBAN Magazine.