Has the cul-de-sac hit a dead end?

It was sold as the great suburban dream — a quiet enclave where children could play safe from cars, where neighbours could catch up for a chin wag, and where the only cars were those owned by locals.  

But instead of reaching that utopia, we took a U-turn.  

Welcome to the cul-de-sac, the road design created with the best of intentions, that never quite achieved its goals.  

After dominating residential design for nearly 50 years, the cul-de-sac has fallen out of favour for many urban developments, despite remaining popular with buyers.

So how did we find ourselves reversing direction?   

The origins of the cul-de-sac 

The name cul-de-sac has the unromantic French translation of ‘bottom of the bag’ but its history usually begins in a small US town named Radburn, New Jersey. 

In the late 1920s, two architects used Radburn as a blueprint for a garden city where traffic on major roads could be separated from quieter suburban streets — a firm rejection of the much more common gridiron road networks used at the time.  

It was to be “a town where roads and parks fit together like the fingers of your right and left hands. A town in which children need never dodge motor-trucks on their way to school,” wrote one of the lead designers.  

Rather than feature a network of parallel and perpendicular streets, Radburn sprouted loopy roads with lollipop cul-de-sacs, like leaves on curving branches. There were other curious elements, including ‘back’ yards that faced the street and front gardens that could be shared or overlap.  

Houses were planted at angles and public areas blurred into communal spaces. Developers liked that they could fit additional blocks into space saved at the top of the loop, while residents loved what they saw as an extension of their private domain, so the design took off.  And once adopted, cul-de-sacs and Radburn-esque layouts fast became a staple of mid-century urban design.  

Courting the cul-de-sac 

As cities across the US and beyond adopted elements of Radburn, success stories became urban lore. 

The retrofitting of cul-de-sacs into a troubled neighbourhood in Dayton Ohio, was credited with cutting traffic by two-thirds and crashes by 40 per cent. Crime fell, values rose, and the popularity of cul-de-sacs soared.  

In Australia, Radburn influenced the design of suburbs from the Crestwood Estate in Thornlie (reportedly described as the most perfect Radburn scheme in the world), but also areas in South Hedland, Withers in Bunbury and swathes of City Beach.  Each area was peppered with cul-de-sacs and interconnecting parks. 

More than 1000 WA roads are officially described as cul-de-sacs by Main Roads, but there are thousands more chases and places, courts and closes, plazas, retreats and mews. 

Competition from buyers made cul-de-sac locations more attractive and at least one study found a 29 per cent price premium over homes on a grid.  But somewhere along the way, the dream of the perfect neighbourhood went awry.  

“The thinking about Radburn and this type of design was that we could get away from high vehicle speeds and areas that were highly permeable for cars, and come back to opening up cul-de-sacs for the community to use,” says Cameron Leckey, President of the Planning Institute of Australia and Director of town planning consultancy Rise Urban.  

“It was a philosophy that was never implemented fully, and in Western Australia we got a watered-down version that was the worst of both worlds. 

“Rather than getting the full Radburn vision of streets that would terminate at parks and open out for pedestrians, we ended up with something that was a bit too vehicle friendly, but also not pedestrian friendly.” 

The very thing that made a cul-de-sac appealing was also its greatest weakness.

Tucked away from main streets, often connected to a long curving crescent, residents found it harder to walk to local amenities like shops or schools. They were too small for buses to navigate so the car became the default option.  

Where cul-de-sacs lacked connection points for pedestrians — paths that could lead from one road to another in a straight line — they were found to increase traffic rather than decrease it, as residents gave up on circuitous walking routes and jumped in the car instead. And with additional driving came additional risks on the road.  

In one influential piece of research, 24 medium-sized cities and 130,000 car crashes in California were studied over nine years. The study found that fatal crashes were much more common in cities with a lower density of people and of intersections. Within individual cities, blocks with higher street network connectivity (and typically fewer cul-de-sacs) had a lower rate of fatal crashes.  

Rethinking the road network 

The next approach was to retrofit pathways into cul-de-sacs to allow people to travel more easily across suburbs, but these presented their own challenges.  

Cameron Leckey has lived on several cul-de-sacs and says the worst had a “bowling alley pedestrian path,” running alongside his Karrinyup house.  

“It was 4m wide and 40m long, and had 2m high fences on either side of it, and we got anti- social behaviour because of the lane,” he says. “It just feels unsafe, and I wouldn't let my kids walk down there on their own.” 

Other research seems to back up those concerns — though there are plenty of critics.  

In the UK, the 35-year-old ‘Secured By Design’ initiative has long argued for the development of cul-de-sacs as a way to limit crime, based on the principle that they were more private and strangers in the street would stand out.  

While this reduces walking and cycling, the initiative’s backers argue that for maximum impact, they should be kept separate to reduce through traffic by pedestrians who aren’t residents.  

More recently, urban planners have questioned whether there is sufficient evidence to justify creating isolated cul-de-sacs at the risk of poor connectivity. In WA, a detailed report carried out for the City of Gosnells back in 2001 also singled out the use of complex cul-de-sac networks as a crime risk, but found some designs were riskier than others.  

Long cul-de-sacs, those where you couldn’t see the end houses easily from the passing street, or those where a pedestrian footpath passed behind the side or rear walls of houses, were linked with a greater rise in property crime, the report found. And houses at the back of a cul-de-sac were also more at risk of burglary than those close to the entry, casting doubt on the idea that it was safer to be tucked away from a major road.  

By 2009, WA planners had decided the cul-de-sac still had a place but needed a makeover.  

The Liveable Neighbourhoods policy set new guidelines for cul-de-sacs, including a maximum length of 120m, a limit per cul-de-sac of 20 dwellings, and a cap on cul-de-sacs to host no more than 15 per cent of homes in a given neighbourhood. Pedestrians and cyclists were also to be given through access, and cul-de-sacs were to incorporate the potential for car access in the future, if traffic volumes required.   

An update in 2015 recommended they be used sparingly but noted the opportunity to create small parks with passive surveillance from nearby houses.  

Tim Judd from transport planning consultancy PJA, says the rethink means cul-de-sacs are more than dead ends. Instead, modern cul-de-sacs act as ‘modal filters’, helping to limit vehicle traffic while encouraging easy connectivity for pedestrians and cyclists.  

“Much of our work is breaking traffic links up with cul-de-sacs and introducing connections between them for walking and riding, so the paths that connect the cul-de-sac end up like micro parks,” says Judd, who is also a board member of advocacy group Streets for People. 

“I’m working on subdivisions where we can say there's no reason why people need to drive through this section. They've got a main road that they can drive on and they can access this road from either end. Let's close off the middle bit and have a park.” 

As blocks get smaller and neighbourhoods get denser, having pocket-size parks creates new ways for people to get outdoors and enjoy some greenery, Judd says.  

“Cul-de-sacs do provide that old Aussie dream of kids playing out on the street, because it's a safer environment,” he says. “With lots and gardens getting smaller now, it extends their playing space. We are repurposing the road space for things other than cars.” 

Cameron Leckey agrees and says cul-de-sacs offer other advantages, including being able to use land more efficiently, such as odd-shaped blocks or properties that abut bushland or wetlands where a road can’t run.  

Creating safe and welcoming neighbourhoods 

RAC manager Transport Planning and Policy, Aron Holbrook, says taking a more creative approach to cul-de-sacs, and neighbourhood design overall, is critical to ensuring people can move about easily.  

This means looking at connectivity (the number of connections between locations), permeability (how easy it is to move from one place to another) as well as legibility (how easy it is to understand where you are and where you’re going).  

“What you'll find within a traditional cul-de-sac or curvy road system, is that you often lose track of where you've been. Am I still going north? Have I actually shifted and I’m facing east or west? You can lose orientation,” Holbrook says.  

“In a strong grid network, it’s pretty easy to understand where you’re going.” 

Aron Holbrook says good design should consider the movement of people using all modes of transport, and make active travel safer and easier. Beyond this, good design should also create safe and welcoming places that enable greater social interaction.  

“Traditionally we had a grid system, then the pendulum swung away and we had a spaghetti pattern of cul-de-sacs,” he says. 

“Now we’ve arrived somewhere in between, realising a mix of both is not a bad thing — as long as it’s designed well and works well for everyone working, living and interacting in that space.”