We have shown in this research that the problem on suburban housing estates is not that there are too few parking spaces, there are in fact a surplus. However the low level of garage use and the inflexibility of the way that parking is allocated means that this apparent surplus can exist alongside huge levels of reported parking tension. On all of the estates that we surveyed, car parking spaces remain unused by one household while their neighbours are parking on pavements and verges and even their own front lawn much to the annoyance of everyone involved.
Parking and car ownership levels: The first question that we have sought to answer is whether the amount of parking has an impact on the level of car ownership. Figures 10 and 11 suggest that there is a rough correlation between the amount of car parking provided with a house and the number of cars owned. At the margins if people can’t find a convenient parking space they might question whether to buy a second or third car.
However our survey work, focus groups and case studies suggest that this effect is limited. In only one of our case studies did we observe an apparent reduction in car ownership as a result of parking restrictions. This was the scheme where parking enforcement was in place so that there was literally nowhere to park other than in allocated spaces. This however was achieved at the expense of the highest levels of parking tensions. In other schemes where on-street parking was allowed, or where restrictions were not enforced, the surplus cars simply spilled onto the street undermining the deterrent effect.
Recommendation 1: Reducing car parking on suburban estates should not be regarded as an effective way of reducing levels of car use and ownership.
Car reliance: In the minds of the residents of these estates a car is an essential part of their daily lives. The prediction made by Colin Buchanan that cars would be taken for granted as much as an overcoat appears to have come true. Most of the people we surveyed see life without a car as impossible and many aspire to have as many cars as there are adults in their household. This suggests that on certain suburban estates we have reached a point similar to many American suburbs where walking is considered an aberration and where people without access to a car, such as the elderly, find it impossible to live.
However when we looked at the context of the six case study estates it was not true that they were so isolated that walking was impossible. In most cases there were shops, bus stops and schools within a five minute walk (400m). Yet it is almost certainly the case that residents were undertaking trips to all of these places by car. Part of the reason for this is the economics and psychology of car ownership. Once you have invested in a car it is economically sensible to use it as much as possible. And once the car is sitting on your drive it takes a force of will to squeeze past it, walk to the local shops or take your kids to school. Pretty soon it feels like there is no choice but to use the car for most trips.
However the design of the case study estates does not always help. Three of the case studies were cul-de-sacs – mostly because of the configuration of the site and the available highway access. In these cases households located away from the entrance had a long and tortuous route if they chose to walk or cycle. In the other three case studies the designers of the estates had clearly tried to improve walk-ability and permeability. However these improvements were largely internal to the estate and there remained a problem with the way that they connected (or not) to surrounding areas. The two Kings Hill schemes, for example, had ‘walkable’ lanes running east/west through the estate. However the most direct route to the local centre would run north/south. In both cases it was possible to walk this north/south route, but it meant passing through tertiary routes, crossing a major road and then walking across the car park to a supermarket. It is not surprising that people drive.
Recommendation 2: Allocated parking spaces should cater for the average parking requirement of households based on the house size. Unallocated spaces should provide for at least 20% additional spaces.
Parking provision: Which brings us to the question of how much parking should be provided? Even if reducing parking does not impact on car ownership there remain good reasons not to allow a free for all. Quite apart from the inefficiency of land use and the environmental impacts on estates, if we were to cater for the maximum possible needs of each household we would end up creating far more parking than we need. The most efficient solution would be to have all spaces unallocated. If this had been the case in Kent then the overall level of parking could have been reduced by as much as half a car/house. This explains why Victorian streets even with quite high levels of car ownership work better than most of our case studies. The problem is that housebuilders would struggle to sell a house with no allocated parking. So we need a mix of allocated an unallocated.
Our suggestion therefore is that the maximum number of allocated spaces be linked to the likely average level of car ownership. This is likely to be based on the data in Figure 4 namely that 1 and 2 bed houses and flats would have 1 parking space, 3 bed units would have a mix of 1 and 2 spaces (probably depending on their location) and 4 bedroom and above would have 2 spaces.
Ideally this figure would include garages. However, this is not going to be the case with garages that are little larger than a 2.4m parking space. If garages are to be counted they need to be at least 3m wide internally. Garages tend to have driveways in front of them so that they create 2 parking spaces. Provided that they are large enough to use, it is sensible for them to be counted as part of this allocated provision because people then can make a choice about whether to use them.
This level of allocated spaces will only work if there is a pressure valve of unallocated spaces to take up the slack. In our case studies the observed level of parking outside allocated bays varied greatly but in the three estates visited early on a Saturday morning it was 50% or more. Some of this was the result of people preferring to park informally on-street rather than in designated bays in rear parking courts. It is difficult to be precise but the suggestion that there should be at least an additional 20% of unallocated bays on top of the allocated provision is reasonable.
Recommendation 3: Estates should be more effectively integrated into their surroundings by creating clear, legible and safe routes to local facilities.
The design of estates: The parking problems observed in the case study estates are not necessarily the result of bad design. On the contrary the case studies exhibit the type of dense, village character development that many housebuilders have developed as a response to national design guidance. The houses are built to the back of pavement, streets are reduced to as little as 10m between buildings and densities are generally higher than 40 units/ha (compared to an average of 23 units/ha all housing schemes in the early 1990s).
It is difficult to avoid the conclusions that the problems with parking on these estates are at least partly the result of the way that they have followed national design guidance. Traditionally, allocated, on-plot parking was provided on a driveway in front of the house. With semi-detached units a second space could be provided in a garage, down the side of the house. These front driveways meant that houses had to be set back 6m from the pavement creating very wide streets with a suburban character.
Urban design guidance has suggested that streets be much narrower to create the more urban, village street character that we see in our case studies. Design guidelines and density standards have also tended to favour terraced houses rather than semis. This has meant that the quality and character of the estate has improved along with its popularity with residents (based on our survey). However it also means that the traditional driveway parking space has been squeezed out of existence.
This design-based approach means that new solutions are needed for parking. In the cases the solutions tended to be; town houses with integral garages, some semis with parking down the side of the house and for all other units rear parking courts. As designers we know that it is possible to develop housing estates up to 30-35 units/ha using semi-detached units. These can be built to the back of pavement to create a dense village feel while 200% parking can be provided out of sight, down the side of the property.
Once densities rise above this level – as is desirable – then it is necessary to use terraced houses. In order to provide parking it becomes necessary either to reintroduce the front driveway, provide allocated parking on-street or to create rear parking courts. Driveways tend to be resisted by the planning authority and allocated spaces can only be provided on streets that are unadopted. So in many cases parking courts become the only option. These however are not popular and our case studies suggest that some people will avoid using them if they are able to park informally outside their house. It does however appear that parking courts work best if the parking space is linked to the back garden of the house, if the parking court is small and provided that the cars can be overlooked. In some cases it may even be appropriate for the parking court to be gated.
In our view the street should be the place where unallocated parking is provided. This will require a rethink of the way that these streets are designed. The narrow winding lanes in our case studies mean that parked cars inevitably need to be partly on the pavement and even then they look out of place. A better solution would be a robust ‘Victorian Street’ wide enough to accommodate parked cars. This suggests a carriageway width of 7.5m rather than the 4.5m found typically in our case studies (see Figure 16). This would allow cars to park on either side of the street leaving a 3.5m carriageway – which would mean that cars would still need to give way to oncoming traffic.
These suggestions, combined with clearer, more permeable layouts that are integrated into their surroundings create the potential for an alternative suburban form. This can potentially achieve densities in excess of 40 units/ha, provide for the levels of parking suggested above and create urban walkable neighbourhoods. To illustrate this potential we have redesigned one of our case studies below:
Recommendation 4: That design guidance for new estates should be amended to allow for wider streets to accommodate on-street parking and more permeable integrated layouts.
For many years, URBED has pursued the idea of the Sustainable Urban Neighbourhood1. Part of this has been concerned with the reduction in car use as part of a wider environmental agenda. This environmental imperative is as strong today as it has ever been if we are to meet our climate change targets. Transport is the only source of CO2 emissions that continues to rise and successive governments have sought to reduce car use.
This research challenges one of the orthodoxies of sustainable urban planning, namely that the reduction in parking is an effective tool to reduce car use. Our findings would suggest that it isn’t, at least in the suburban estates that we have studied. So strong are the pressures to have and use a car that people will find a way around parking restrictions. If the restrictions are so strong that they are unable to do this, they will be very unhappy, tensions will rise and the community will suffer. It is the pressures to have and use a car that we need to address rather than the level of parking on new estates.
One response to this would be to say that this is only to be expected if we continue to build houses in car-reliant suburban locations. This is why we would like to undertake a companion research project to ask the same questions of schemes within urban areas. However, given the need for housing in the country and the loosening of restrictions on greenfield development it is likely that this type of housing will increase. We therefore need to reconsider our approach to the provision and design of parking which in turn will mean a new approach to the design of these estates.