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Home Zones Guidance Consultation

5 Transport Considerations

Key design principles

Requirements

5.1 The underlying principles of Home Zones have been explored in previous parts of this document. Key themes include a sense of community ownership, extended use of shared surfaces and the promotion of sustainability. In transport terms the design of a Home Zone should deliver an environment where:

• motorists do not perceive that they have priority over any other users of the space;
• vehicles cannot practically proceed at speeds much faster than walking pace;
• sustainable transport modes are both enabled and encouraged;
• requirements for parking are balanced with other design considerations;
• access is maintained for service vehicles, and to underground utilities; and
• maintenance of the Home Zone is both affordable and easily undertaken.

Size of a Home Zone

5.2 If a Home Zone is too small there is a risk that the key aims will not be achieved since the critical mass of community ownership will not be developed. On the other hand, if the Home Zone is too large there is a risk that it will lose identity and any sense of community ownership will be watered down. There may also be a problem establishing self-enforcing speed management measures. Dutch experience shows that driver frustration increases when the distance to travel out of the Home Zone is greater than 500m. The primary guide to the size should be the existence of a definable geographic area with an existing or potentially viable and coherent community together with any limitations imposed by peak hour traffic flows and parking demand.

5.3 Demand for larger Home Zones could be met by establishing a network of schemes within a wider conventional traffic calmed area or 20 mph zone.

Traffic flows

5.4 Low traffic flows, and minimal through traffic are essential for a successful Home Zone, allowing a variety of street activity and perceptions of community ownership. For this reason, the Home Zone should not be located on a major through-route.

5.5 When considering traffic flows, the most critical time would be between the end of the school day and early evening. It is during this period that there is greatest potential for conflict between moving vehicles and people using the street. European experience suggests that a maximum average two-way flow of 100 vehicles per hour would be appropriate during this period.

On-street parking

5.6 The demand for parking will be a function of housing density, car ownership, and opportunities for off-street parking. It may also reflect use of the area by commuters or shoppers during the day. Innovative approaches may be required where demand for on-street parking exceeds the availability of parking spaces.

Self-enforcement

5.7 The design of Home Zones should be such that parking and speed control measures are self enforcing. There are unlikely to be either the resources available, or willingness for on-going policing and enforcement of such residential areas. The physical layout and design of the shared space and traffic calming measures should therefore limit vehicle speeds to not much more than walking speed. Parking areas should be well defined with little or no opportunity for parking elsewhere in the street.

5.8 A successful Home Zone will promote the conditions for informal 'community policing' of the area.

Highway priorities

5.9 The Transport (Scotland) Act 2001 does not give priority to pedestrians and cyclists over motor vehicles. Home Zones should, however, aim to promote the perception amongst motorists, cyclists and pedestrians that all users have equal priority. The elimination of kerb lines, and creation of carefully designed shared spaces marked by prominent gateways will mark the Home Zone as being a different kind of road environment. The aim should be to give motorists the impression that they are guests within the Home Zone.

Hierarchy of users

5.10 Scottish Planning Policy (NPPG17: Transport and Planning, paragraph 20) recognises the need to prioritise accessibility for individual travel according to a general hierarchy, as follows:

• walking;
• cycling;
• public transport;
• private cars.

5.11 The design of the Home Zone should reflect this hierarchy. For example, pedestrian links should be direct and of high quality; appropriate cycle facilities should be integral to the design; there should be high quality public transport linkages a short walk away; and traditional vehicle road space should be re-allocated to more sustainable modes.

Identity of a Home Zone

5.12 It is essential that the Home Zone has a strong and unique identity, both to clearly distinguish it from the surrounding road network, and also to engender a sense of community ownership and control. This identity should closely reflect the local context _ in terms of housing design, shape and character, existing routes and movement, and the planting of trees and other vegetation.

5.13 The gateway is an important feature in defining the boundary of the Home Zone. Clear signs must be erected in accordance with the Traffic Signs Regulations and General Directions (TSRGD). The following should also be considered:

• an emphasised visual threshold, with a change in surface texture and colour, and associated vertical measures such as signs, posts or trees;
• an emphasised physical threshold, such as a speed table, and rumble strips; and
• a narrowing of the roadway width at the gateway to a 3.5m vehicle running track.

5.14 There is considerable scope for community involvement in the design of the gateway, which will help reinforce a local identity. Any themes included within the gateway could be repeated throughout the Home Zone.

Home Zones should have good pedestrian
and cycle links to surrounding area.

5.15 Within a successfully designed Home Zone, the layout of the shared surface and the extent of traffic calming measures should ensure that drivers will be in no doubt as to the environment through which they are driving. There should be minimal or no requirement for repeater 'Home Zone' signs in most schemes.

Transition between Home Zone and road network

5.16 The transition between the Home Zone and the surrounding road network should ideally be located at the junctions where the Home Zone takes access from the surrounding road network. At these locations vehicles will already have slowed to not much more than walking pace. Creating an effective gateway on a straight section of road will be more demanding, and is not necessarily recommended.

5.17 The Home Zone gateway itself should be located between 10m and 20m back from the junction stop line. This enables any vehicles waiting to enter the gateway to do so safely, off the main through route. It also allows any queue of vehicles waiting to emerge onto the main carriageway to be accommodated, without blocking the gateway area. The effective road width on the approach to the gateway should be 5.5m, allowing two vehicles to pass.

Typical arrangements for a Home Zone gateway.

Wider area impacts

5.18 The creation of a Home Zone may cause knock on effects for the surrounding road network particularly in terms of displaced on-street parking and traffic movements. The likely extent of this problem should be carefully considered and quantified, and if appropriate dealt with as part of an area-wide traffic and parking management strategy. This is unlikely to be a consideration in new build Home Zones provided there is capacity to accommodate residents' and occasional visitors' parking requirements.

5.19 On a more positive note, there is considerable scope for Home Zones that complement wider area initiatives such as safer routes to school programmes, or pedestrian and cycle networks.

Traffic noise levels

5.20 Whilst the creation of a Home Zone may well result in a decrease in vehicle speeds from say 25 mph to 10 mph, this will not necessarily result in a proportional decrease in noise levels. Changes in road surfaces, and the introduction of traffic calming features such as speed humps could increase traffic generated noise.

5.21 Further increases in traffic-related noise could come from the introduction of parking arrangements requiring more complicated vehicle manoeuvres, and an increase in exposure to noise from in-car stereos due to decreased vehicle speeds.

5.22 Other sources of traffic-related noise may be totally unaffected by the creation of the Home Zone. This includes stationary vehicles temporarily parked with their engines left running, or the nuisance from car alarm systems either being switched on or off, or being triggered.

Air pollution levels

5.23 It is unlikely that creation of a Home Zone will impact significantly on local air quality. This is more likely to be influenced by factors such as prevailing weather conditions, neighbouring sources of pollution, and urban form, none of which would necessarily be changed by the Home Zone. However, by encouraging drivers to adopt a more gentle driving style, a contribution can be made to local reductions in pollutants emitted from vehicles. This could benefit other users of the Home Zone and encourage people to make greater use of the street space.

Designing for vehicles

Key principles

5.24 The over-riding principles of new build Home Zones should be in accord with the advice set out in (DETR, Places, Streets and Movement _ A companion guide to Design Bulletin 32). The design of new developments should be based on a network of spaces rather than a hierarchy of roads. A legible network of spaces can include squares, courtyards, and pedestrian only streets and lanes, and should reflect the local built form. Building lines should define spaces in the first instance, rather than spaces being defined by standard road widths and geometries. This approach helps to ensure that roads do not overly dominate areas, and contributes to the development of a unique character and identity.

5.25 Attempting to alter the existing spatial framework of an established residential environment is unlikely to produce a satisfactory result. The focus should be on the re-allocation and re-definition of existing spaces.

Vehicle running track

5.26 A vehicle running track should be established within the Home Zone, designated by landscaping, parking areas, bollards and building lines. Ideally there should be no vertical distinction between the vehicle running track and footpath, in terms of a kerb line. Well-designed schemes will manage to reduce the typical linear characteristics of normal streets such as kerb lines, road markings and rows of street lights.

5.27 The width of the vehicle running track should be the minimum possible, typically between 3.0 and 3.5m, in order to control speed. Inter-visible passing places should be provided no greater than 35m apart. The running track should be at least 5.5m wide in these locations, allowing two service vehicles to pass one another. The passing places should be designed so as to deter people parking in these locations.

5.28 Speed reducing measures should be included within the vehicle running track, located no greater than 35m apart. This ensures that vehicle speeds are kept at a uniformly low speed. Speed reducing measures should, if possible, be designed as integral elements of the Home Zone, rather than as 'add-ons'.

5.29 Horizontal deflections around designated parking areas and landscaped areas are an ideal way to achieve this. Ensuring that radii of any corners within the vehicle running track are as small as possible also contributes to lower vehicle speeds.

5.30 Sections of one-way vehicle running track should be avoided, as typically vehicle speeds increase due to the absence of on-coming traffic.

Swept path analysis

5.31 The provisional vehicle running track needs to be rigorously tested and adjusted to ensure that vehicles can actually pass through the Home Zone area at a low speed, and make all necessary manoeuvres without damaging either the vehicle or street furniture. Computer tracking programs are available which plot the swept path of a wide variety of vehicles onto proposed layouts, enabling identification of where the width of the running track can be either reduced, or increased.

5.32 Within a residential area, the largest vehicle requiring regular access is likely to be a refuse collection lorry. The vehicle track will have to ensure that such vehicles can be readily accommodated. Similarly, although fire engines and ambulances are infrequent visitors, adequate access should be provided to limit delays. Close liaison will be required with refuse collection operatives and the emergency services to enable the development of a satisfactory solution.

5.33 Large removal lorries should also be capable of being accommodated within the Home Zone, however, it should be borne in mind that such vehicles are only infrequent visitors to residential areas. Accordingly, such vehicles may be required to be driven with more care and attention. Over-run areas can be incorporated into many of the speed reducing measures, which allow for the passage of larger vehicles at low speeds, but are more difficult for cars to negotiate.

Junctions within a Home Zone

5.34 If routes cross within a Home Zone, this can be indicated in both the character and form of the surface treatment. It is important that no explicit right of way is signified within the Home Zone, as this uncertainty ensures that drivers adopt a more cautious driving style.

5.35 Detailed consideration should be given to the design of sightlines at internal junctions within a Home Zone, and it is advised that individual assessment is undertaken in all cases to reflect individual circumstances. Whilst sightlines should never be reduced to a level where danger is likely to be caused, the provision of sightlines above recommended minimums is not advised as this could result in vehicle speeds which are too high.

5.36 Existing guidance for areas where both streets forming the junction are within a conventional 20 mph traffic calmed area require a sightline of 33m along the major road, from a point 2.4m back from the junction stop line on the minor road (DETR, Places, Streets and Movement, 1998). Within Home Zones, such distances are considered to be the maximum desirable in order that vehicle speeds are not too high.

Sight line analysis at a junction based
on maximum speeds of 20 mph.

5.37 A minimum major road sightline could be calculated from a first principles approach. Based on a maximum 10 mph design speed, a 2 second reaction time, and a wet road braking rate of 7.0 ms-², the minimum major road sightline would be just over 12m. The minimum advisable distance from which this should be obtained on the minor road should not be less than 2.0m, as this would require significant encroachment onto the junction to obtain safe visibility of on-coming vehicles.

Parking layout

5.38 Home Zones should provide adequate levels of parking for residents and potential visitors. By the re-allocation of road-space, and the re-arrangement of parking patterns, the efficiency of existing parking provision can be increased. In new-build schemes, the total amount of on and off-street parking can be determined from consideration of the number and type of dwellings, and reference to relevant parking standards documents. A first principles assessment of any similar residential areas in the vicinity of the development may be more appropriate to account for local characteristics of car ownership.

5.39 New build Home Zones provide opportunities for the introduction of car-free, and car-reduced housing schemes, provided the basic criteria for such schemes can be met. These include vicinity to a high frequency bus route and shopping facilities, location within a controlled parking zone, establishment of high quality and attractive pedestrian and cycle facilities and links, combined with an effective management regime. These criteria are fully compatible with the Home Zone concept.

5.40 On-street parking should be provided in the direct vicinity of people's homes, enabling vehicle owners to overlook their vehicle from their property. Some parking may be able to be provided at the side or to the rear of buildings in order that the parked vehicles do not form a barrier between the houses and the Home Zone space. However, it should be recognised that the majority of adult street activity is often related to the walk between the house and the car.

5.41 On-street parking can be arranged to be parallel to the building lines, arranged in chevrons, or perpendicular to building lines. Blocks of parking can be used to define the vehicle running track through the area, introducing horizontal deflections. Parking should be broken into discrete units, so that parking does not dominate the Home Zone area.

5.42 Swept path analysis of all parking bays will be essential, to ensure that they can be easily used by manoeuvring vehicles.

Vehicle swept path analysis should be used to ensure that all parking bays are physically accessible, and that the vehicle running track is wide enough to accommodate the
vehicle path.

Parking control

5.43 Individual parking bays should be marked out using road surface markings, or different coloured paving blocks. Careful design should eliminate the need for further signage. Parking bays should also be separated from the vehicle running track, to ensure that when the parking bays are empty, vehicles cannot cut across them.

5.44 If schemes are well laid out, there will be few opportunities for parking outwith marked bays. The design should therefore take account of the likely level of demand for on-street parking including any non-resident parking.

Designing for pedestrians

5.45 The Home Zone area should be designed to be totally accessible for the movement of children, disabled people and older people. The Home Zone should also be designed so as to provide direct, accessible, and attractive links to local amenities and public transport facilities. This may require works outwith the immediate Home Zone boundary.

5.46 Provided vehicle speeds are successfully reduced to not much more than walking pace, then accidents involving pedestrians should reduce in number and severity. However, particular attention is required at critical locations, such as where children may be expected to congregate, to ensure that any highway or landscaping features do not impede visibility between children and vehicles. In all cases, it is recommended that objects that may obstruct the visibility of small children and toddlers are not placed within 1.5m of the vehicle running track.

5.47 Within the shared space area, thought can be given to the desirability of establishing pedestrian only areas. These will probably be where seats or play equipment have been located, but may also be used to form a series of pedestrian refuges along the length of the Home Zone. Such areas should be greater than 1.2m in width to allow space for two passing pedestrians, or a wheelchair, or a parent with pushchair and toddler.

5.48 Thorough consultation with local groups representing older people and disabled persons should be undertaken throughout the design and implementation stages of the Home Zone. The aim should be to reflect particular local requirements to provide a clear, legible and useable layout for all potential users of the space.

Designing for cyclists

5.49 Given the low traffic speeds and low traffic volumes, Home Zones are likely to be an attractive environment for cyclists of all ages. This should be encouraged both by the provision of suitable cycle storage facilities and connections to a cycle network that links to key surrounding destinations.

5.50 In new-build Home Zones, it is recommended that each property provide opportunities for the secure and covered storage of cycles, which can be easily accessed from the ground level. This could be within an outbuilding, or internal to the building. In retrofit Home Zones, consultation and evaluation of existing practices can determine the requirement for additional secure and covered cycle storage. Additional storage facilities should be provided on-street in the form of Sheffield style stands which allow the cycles frame and wheels to be secured.

Designing for public transport

5.51 Whilst the Home Zone concept lends itself to the promotion of sustainable forms of transport, it is unlikely that regular bus routes can be successfully incorporated as part of the Home Zone. Instead, the emphasis should be on providing convenient and direct pedestrian links to frequent and high quality public transport services. Attention should be paid to the quality of the bus stop/shelter, and also to the adequacy of service information provided.

Designing for utilities

5.52 In existing residential areas, utility companies maintain a variety of apparatus both below ground and above ground. It is essential that access to this apparatus is provided, both for planned and emergency access. It will be important that all manholes and service covers can be accessed without blocking the vehicle running track, and allowing for a utility vehicle to be parked nearby.

5.53 As utility diversions can be expensive and complicated, it is likely the pattern of utilities will determine to some degree the design of the Home Zone in retrofit schemes. There may be opportunities to rationalise or upgrade utility infrastructure at the time of Home Zone implementation. Within new build Home Zones, there is an opportunity to plan the locations of utilities so as they do not conflict with other elements of the Home Zone environment. Close liaison with utility companies will be required throughout the design and implementation stages.

Lighting

5.54 Skilful lighting design is an important element to enhance the features of the Home Zone and to ensure that drivers have sufficient information about the road layout and the presence of speed reduction measures. While it is necessary to ensure that traffic calming features within the Home Zone are sufficiently illuminated there will be no statutory requirement to provide lighting for individual road humps. There will also be no statutory requirement to provide warning signs for individual traffic calming features or road humps.

Lighting is an important part of the Northmoor Home Zone.
Better lighting makes the street safer and more attractive at night.
Lighting levels are dimmed to normal street lighting levels at midnight.

5.55 Higher levels of amenity lighting could be deployed in specific areas within the shared area where people may be expected to gather or where there is a need to address issues of personal safety and security. Lighting in these areas can be dimmed to provide normal illumination levels after specific times.

5.56 In order to reduce street clutter and obstructions for pedestrians, the possibility of mounting street lighting on building facades is an option. This requires careful consideration of positioning to minimise any glare into the rooms of the buildings, and also a legal agreement with householders.

5.57 In line with the requirements of sustainability, lighting designs should seek to be energy efficient, whilst limiting extraneous light pollution.

Drainage

5.58 Effective drainage of the shared use surface is very important, in order to achieve an attractive and useable area for the residents. Some areas in Scotland are particularly demanding in this respect, and a very careful design will be required. The shared surface should drain away from the dwellings, to be collected at frequent intervals in gullies or similar.

5.59 In retrofit Home Zones, it is likely that the existing road and pavement drainage will be utilised. In these situations, it will be important to check that any newly introduced elements do not obstruct the drainage of surface water.

5.60 In new build Home Zones, there are opportunities for the introduction of sustainable urban drainage systems, which aim to reduce the rate and volume of surface water run off.

Maintenance

5.61 The design of the Home Zone should allow for cost-effective, and straightforward maintenance. This includes the maintenance of the 'bricks and mortar' as well as cleaning, and maintenance of the vegetation. The ongoing resources required for this maintenance should be agreed and sourced from the outset of the scheme.

5.62 Materials and street furniture used within the Home Zone should be of a durable and hardwearing nature. They should be carefully chosen to fit in with the local context. Furthermore, they should be such that they can be easily and inexpensively replaced if necessary. The sustainability of the resources used, and associated maintenance regimes should also be considered.

The choice of materials should strike a
balance between cost, ease of maintenance and quality.
Imprinted tarmac has been used in the Northmoor Home Zone
to create the impression of block paving but at lower cost.

5.63 A successful Home Zone will engender a feeling of ownership and involvement. Planting strips next to dwellings can be provided to encourage residents to have a positive impact upon their street environment.

Summary

5.64 No two Home Zones will be alike. It is important that Home Zones are developed not with slavish adherence to rules and guidance, but with local creativity and a consensus to develop an area that works for those that will use it. This clearly indicates the importance of the recommended bottom-up and inclusive design process. The following list of questions could be used to test the evolving design at relevant stages of its development.

• Have the key principles and goals of the Home Zone been understood and effectively applied to the design?
• Is the size and location of the Home Zone appropriate?
• Can parking demands be managed and well-allocated?
• Have walking, cycling and public transport been effectively promoted?
• Can the design effectively reduce and control vehicle speeds to not much more than walking pace?
• Has full consideration been given to the requirements for utility, servicing and emergency access?
• Has the lighting system been designed in accordance with the principles of the Home Zone?
• Will the surface drainage system work efficiently?
• Can the Home Zone be effectively maintained in an affordable and sustainable manner following construction?

   

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