This article was published in 2019, in Magazine 142.
The design and layout of any new development is critical to how the new residents travel around. Do they always drive a car, do they sometimes choose to walk or cycle, or do they use public transport? The placement of key buildings, such as schools and businesses, the layout of the streets and paths that connect to those buildings, and the design of spaces to welcome people into the development are critical to the success of any new place.
Most new developments around Cambridge fail to deliver most of the promised community. They lack social cohesion owing to too much traffic going through the middle of where people live, designing most of the infrastructure for those who have a car and failing to make it easy to walk or cycle within the development. They includes ‘cycleways’ around the outside as if cycling is only used for exercise and not for going to school or the shops or the bus stop or station.
In this article we will show how a development can be structured, key buildings placed, and cars and people accommodated without forcing everybody to drive. We will use examples from other places to show how a successful community can be created. And, despite many current developers seeming to be under the presumption that the planning system prefers the broken car-first development model. We’ll show that places that put people first even allow developers to make lots more money.
People and not traffic
If we consider a new development with 10,000 dwellings, where each dwelling has two cars and these are driven independently to a remote place of work, then that is 40,000 vehicle movements a day through the development. This ignores the evening trips to visit friends, or to go shopping, so this is a generous approximation. In South Cambridgeshire only about 70% of adults are economically active, which would reduce this number to 28,000 cars a day. These cars have to be accommodated both on the roads within the development and on the road network outside. This is why places like Cambourne and Northstowe that have been designed to encourage the use of the car have had new dual carriageways built or existing dual carriageways widened in a futile attempt to deal with all this traffic.
Back in the 1960s, the impact of car traffic on streets wasn’t well understood, and maybe it still isn’t. In San Francisco, California, a study was undertaken by urban design professor Donald Appleyard on three streets with different levels of traffic: the first on a quiet street with just 2,000 cars a day moving along it, with a peak of 200 cars an hour; the second on a busy street with 8,000 cars a day, with a peak of 550 cars an hour; the third on a main road with 16,000 cars a day, with a peak of 1,900 cars an hour. Appleyard’s research is critical to understanding why throwing as much traffic as possible through the middle of a development is anti-social.
Appleyard discovered that on quiet streets with little car traffic there was more social cohesion. People knew their neighbours and chatted all the time. On average they knew over nine people and were friends with three of them. On busy streets, the residents knew just over five people and had on average 1.3 friends. On main roads they knew just over four people and had less than one friend on average. Car traffic is anti-social.
Appleyard discovered that on quiet streets with little car traffic there was more social cohesion
In 2011 a similar study was conducted by Hart and Packhurst in Bristol with pretty much the same results. Streets with less traffic meant people had more friends and acquaintances. The more people you know the friendlier is the place where you live, the more pride you will take in your street, and the more likely you will be to allow children to play in the street with their friends.
The same is true when travelling between parts of a settlement. The main barriers to movement, especially of vulnerable people like the very young and very old, are the main roads. In a typical new development these main roads go through the middle of the development, capturing all the car traffic and funnelling it past people’s homes. This divides the settlement into blocks of car-dominated streets segregated by very busy main roads that are difficult and dangerous to cross.
Out and around
The best way to resolve the above problem is to separate the mass movement of cars from the majority of people. The proven method to achieve this is something called segmentation. This model has been applied in many places, including Houten in the Netherlands, Ghent in Belgium, Bar Hill, and central Cambridge. The only differences between these are the areas covered and the sizes of the segments.
A segment is an area where for each dwelling there is only one route to and from a main road. This immediately means that there is no through traffic within any segment. If you need to travel from one segment to another, you first have to leave your current segment, access the main road network that links the segments, and then enter the destination segment at its access point.
Bar Hill is a local example of how this works, although with walking as the alternative mode of transport and little provision for cycling. There is an external ring road with no expectation that people would walk along that road (although people still do because of a lack of permeability between segments) and each access point allows vehicular access to only a small segment of the development. Replicating this model, but with properly-designed internal cycleways and safe ring-road crossing points could radically improve a new development.
The real key to this segment model is that there should be plenty of permeability between segments for sustainable modes of transport. There should be footways, cycleways, and public transport connections between segments. This allows people to move quickly from one segment to another without having to use any busy or main road. The shops, amenities and public spaces should face the footways and cycleways, thus ensuring that public life takes place where people are walking and cycling, providing vitality and improved personal security.
This model is also cheaper for a developer to deliver. The main roads themselves don’t need a lot of cycle or pedestrian infrastructure as all they are designed to do is move cars as quickly and safely as possible away from where people live to other places. This means that these roads are narrower than in a typical development, taking up less land area and being less expensive to build. These main roads can typically have a 7.5m-wide single carriageway. In the Netherlands they would also place a central reservation down the middle to prevent dangerous overtaking.
This main road will be noisy and polluting, and therefore best separated from buildings with either a physical berm or a sound wall. There will be places along the main road where pedestrian or cycle crossings will be necessary, for example to access neighbouring settlements. These can be provided at key points either using signalised or priority crossings, or by using bridges.
The key to the segment model is that there should be plenty of permeability between segments for sustainable modes of transport
Waterbeach New Town
To illustrate how such a development model works in practice, let’s see how those principles could be applied to the Waterbeach New Town.
The basic constraints of the development include a new station to the southeast of the site, but northeast of the existing village, and access points from the A10 to the southwest and northwest of the site. There are some features that could easily be retained, such as the lake to the west side of the site, and there should be easy access to Denny Abbey on foot and cycle.
The segment model will work best with a single cycle route through the middle along an east-west axis. All the segments will touch but never cross this main cycleway. The main roads will go from the northwest access point, along the north of the development to the railway and then turn south to allow access to the station area. A separate main road will go from the southwest access point along the south side of the development and allow access to the station area. There won’t be a through route for private car traffic.
Between the main roads and the spine cycleway are the segments. The edges of the segments will typically be defined by additional cycleways that allow access to different parts of the new development and the old village on a mainly north-south axis. This creates a grid of cycleways with a 250 to 500 metre spacing.
If you want to drive out of the development, you first walk to your car and then drive away on slow quiet streets shared with people walking and cycling. You would access the main road at the junction for your segment at which point you can drive at a higher speed around the edge of the development away from anybody walking or cycling. The trip length would be a little bit longer than taking a more direct route, but the time required would be less, owing to the faster speeds of travel on the majority of the route, and the pollution would be lower, owing to the less frequent stopping and starting that would be required by driving through an urban area.
However, driving is not the transport mode that is encouraged. Access to the railway station would be quicker and easier by cycle than by car for the majority of the development’s residents. If you wished to travel to Addenbrooke’s, assuming the new Cambridge South station is built, then you would just hop on one of your bicycles, cycle away from the main road to a cycleway between the segments, then to the main spine cycleway, and then towards the station where plenty of cycle parking would be available.
Reducing car trips
There are other proven techniques for reducing the desire to drive trivially short trips. Remote car parking is one of the best. Freiburg, Germany, built a new development with lots of car parking, but all of it was in multi-storey car parks remote from where people lived. They also required that the car parking spaces were purchased at market value, around €22,500, along with an annual maintenance charge.
Remote car parking is a proven technique for reducing short trips by car
Unfortunately, the size of the parking structures far exceeded the demand now that car parking was not subsidised. Whilst the average level of car ownership in the region is approximately 600 cars per 1,000 population, the level of car ownership in this new development is less than 200. However, residents do have easy access to an excellent public transport network closer than the car park and the highest levels of cycling in the area, because walking a couple of hundred metres to a car park to drive a mile to the shops now takes longer than just cycling there.
Sometimes people will go and buy large volumes of stuff from supermarkets and home furnishing stores. The streets next to people’s houses would still allow loading for up to 30 minutes. Deliveries and loading and unloading cars as close as possible to people’s homes will therefore still be allowed. In Freiburg, one parent will walk to the car park, drive the car to the house, load it up with children and stuff before they all drive off.
Thinking of the children
A large proportion of people who move into a new development cannot drive, mainly because they are too young to have a driving licence. However, these people still need to be able to move around the development, visit their friends and go to school. The development model allows the vast majority of these trips to be conducted on the segregated cycleways throughout the development. This means that a 5-year-old child should be able to cycle, accompanied by an adult or older sibling, to primary school.
To achieve this, all the primary and secondary schools and their associated cycle parking should be reached from the cycleways and not the road network. Cycle parking itself should be able to accommodate every child cycling to school, including adapted cycles that could be used by disabled children. This will also reduce the air pollution within the schools themselves.
Secondary school age children should then be able to cycle independently to school. The schools will still need access to the road network for deliveries, but teacher parking could easily be provided at a remote parking structure allowing the teachers to walk the final hundred metres or so to the school.
When people first move into a new development, they have to rethink how they are going to move around, get to work, go food shopping, and how they would visit the hairdressers and other local services. Unfortunately, most new developments build the cycle infrastructure last and this opportunity for a cultural change is lost.
To rectify this, the main cycle spine route must be built before any new dwelling is occupied. This is a perfectly safe thing to do, as all the construction traffic would stay on the main roads, far away from the spine of the development, and within individual segments as they are built out. If these segments were built from the spine route towards the main road, then the new residents can easily cycle to the railway station safely regardless of what construction is happening.
Bus routes can also be easily built into the development. A direct bus route alongside the spine cycleway could allow access from the main station to the employment and Park & Ride site to the northwest of the development. A local bus service could also be run around the outside of the development along the main roads with frequent stops at each segment to allow people to walk, or cycle, a short distance to access the public transport stops.
The building of a new development is an opportunity for radical change in the way people move around, both within the development and across the surrounding area. New developments should be designed to reduce the requirement to drive (especially for trivially short journeys) by designing using the segment model, by building cycleways between the segments and by providing remote car parking.
A new development is an opportunity for radical change in the way people move around
All the key destinations should be along the main cycleways, with the primary and secondary schools, sixth form college, main employment sites and amenities and the railway station all being more accessible from the cycleways than the road network. The road network itself should provide access to every building by car, although car storage would be provided at its true cost in remote parking structures. Short trips – like taking the children to Scouts or to football practice – could be done more quickly and easily by cycle and, if the children are old enough, they could cycle by themselves completely safely because the cycleway network is unravelled from the car network.
Less land is then required for the main road networks, both because fewer cars will be driven, and because the majority of the people moving around will be using very space-efficient modes of transport. This means that more land is available for buildings that make the developers money. These buildings can accommodate higher density development because there are fewer car trips per capita, and therefore this model of development can provide more affordable homes for people who desperately need such housing with the same level of investment in the rest of the surrounding road network.
The development will be significantly healthier than a typical new development, with noise and air pollution levels significantly lower in the areas where people live. With all those children and adults cycling around, obesity levels will be lower, school attainment and productivity will be higher, and road safety will be significantly improved. The development will be more attractive to potential new residents as they will see children playing in the streets, parents chatting to each other, and people cycling and chatting side by side going about their business. Every new resident, regardless of their age, should be given a new city bike to allow them to move around.
I call this style of development ‘pro-people’. All the homes and shops in the development can be accessed by car, but sustainable transport gets priority. The majority of trips would be along quiet cycleways and footways with lots of trees and green space, with access to all the key destinations. This style of development is standard in the Netherlands and other European countries, where they have healthier and happier children and adults.