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1 Streets in context

CHAPTER AIMS

• Provide an historical perspective on streets.
• Explain the distinction between 'streets' and 'roads'.
• Summarise the key functions of streets.
• Propose a new approach to defining street hierarchies, based on their significance in terms of both place and movement.
• Set out the framework of legislation, standards and guidance that apply to the design of streets.

STREETS - AN HISTORICAL PERSPECTIVE

Most places owe their layout to their original function. Towns have often grown up around a market place a bridgehead or a harbour; villages were formed according to the pattern of farming and the ownership of the land. The layouts catered mostly for movement on foot. The era of motorised transport and especially privately-owned motor vehicles has, superficially at least, removed the constraint that kept urban settlements compact and walkable.

When the regulation of roads and streets began, spread of fire was the main concern. Subsequently health came to the forefront and the classic 36 ft wide bye-law street was devised as a means of ensuring the passage of air in densely built-up areas. Later, the desire to guarantee that sunshine would get to every house led to the requirement for a 70 ft separation between house fronts, and this shaped many developments from the 1920s onwards.

It was not until after the Second World War, and particularly with the dramatic increase in car ownership from the 1960s onwards, that traffic considerations came to dominate road design.

1.1 STREETS AND ROADS

1.1.1 A clear distinction can be drawn in functional terms between streets and roads. ¹ Roads are essentially thoroughfares whose main function is accommodating the movement of motor traffic. For the purposes of this document, a street is defined as a thoroughfare that has important public realm functions beyond the movement of traffic. Streets are typically lined with buildings and public spaces, and while movement is still a key function, there are several others, of which the place function is the most important.

1.1.2 Streets have to fulfil a complex variety of functions in order to meet people's needs as places for living, working and moving around in. This requires a careful and multi-disciplinary approach that balances potential conflicts between different objectives.

1.1.3 In the decades following the Second World War, there was a desire to achieve a clear distinction between two types of road:

• distributor roads, designed for movement, where pedestrians were excluded or, at best, marginalised; and
• access roads, designed to serve buildings, where pedestrians were accommodated.

This led to layouts where buildings were set in the space between streets rather than on them, and where movement on foot and by vehicle was segregated, sometimes using decks, bridges or subways. Many developments constructed using such layouts have had significant social problems and have either been demolished or undergone major regeneration (Fig. 1.1).

Figure 1.1 A poor-quality space with a layout where pedestrians and vehicles are segregated. It has not been a success and the area is now undergoing regeneration ( EDAW, Bowmar, Alloa).

1.1.4 This has led to an approach that believed segregated streets were safer streets; we now understand that this is not the case, moreover there have been health and social disbenefits from following such an approach. Creating streets which are places, and changing driver behaviour through the design of our streets, does not create additional risk. Aspects of risk and liability, as they concern the design of streets, are discussed at the end of this chapter.

1.1.5 The conventional approach to network planning also limited the design of multi-functional streets to only the most lightly-trafficked routes. This led to development patterns where busy distributor roads link relatively small cells of housing. Such layouts are often not conducive to anything but the shortest of trips on foot or by bicycle. It is now widely recognised that there are many advantages in extending the use of multi-functional streets in urban areas to busier routes.

1.1.6 Streets that are good quality places achieve a number of positive outcomes, creating a virtuous circle:

1.1.7 Well-designed streets thus have a crucial part to play in the delivery of sustainable places.

1.1.8 Lanes in rural areas can also provide other functions than just movement, including various leisure activities such as walking, cycling and horse riding.

1.2 MIXED AND WALKABLE NEIGHBOURHOODS

1.2.1 It is vital that street patterns are laid out carefully as they are critical to how a place functions; and experience has shown that street patterns last the longest of any aspect of a development. It is very difficult to change a street alignment once it is in place - it will typically be lined by private land in multiple ownership and will carry significant public infrastructure
(Image of an historic Scottish town showing how the street pattern has endured.)

1.2.2 The type of road planning described above has, in recent decades, been accompanied by patterns of development where housing, employment, retail and other facilities were all developed in separate areas, which were often poorly connected with one another, particularly for journeys other than by car.
(Include aerial photograph of Scottish new town - e.g. Cumbernauld)

1.2.3 Government policy now supports the creation of mixed-use neighbourhoods with well-connected street patterns, where daily needs are within walking distance of most residents. Layouts built on these more traditional lines are likely to be more adaptable and will lead to lower car use thus contributing to wider transportation and environmental objectives.

Figure 1.2 (a) dispersed and car-dependent versus (b) traditional, compact and walkable layout

1.2.4 Street networks serving these mixed use areas should, in general, be well connected. Connected, or 'permeable' networks encourage walking and cycling, and make places easier to navigate through. They also lead to a more even spread of motor traffic throughout the area and so avoid the need for distributor roads with no frontage development.

1.2.5 Further guidance on planning the overall layout of neighbourhoods and urban areas is given in Chapter G1.

1.3 PRINCIPAL FUNCTIONS OF STREETS

1.3.1 Streets have five principal functions;

• place;
• movement;
• access;
• parking; and
• drainage, utilities and street lighting.

PLACE

1.3.2 The place function is essentially what distinguishes a street from a road. The sense of place is fundamental to a richer and more fulfilling environment. It comes largely from creating a strong relationship between the street and the buildings and spaces that frame it.

1.3.3 A sense of place encompasses a number of aspects, most notably the street's:

• local distinctiveness;
• visual quality; and
• propensity to encourage social activity.

Guidance on ensuring consideration of the place function is outlined within Chapters G1 and G2.

MOVEMENT

1.3.4 Providing for movement along a street is vital, but it should not be considered independently of the street's other functions. The need to cater for motor vehicles is well understood by designers, but the passage of people on foot and cycle has often been neglected. Walking and cycling are important modes of travel, offering a more sustainable alternative to the car, making a positive contribution to the overall character of a place, public health, social interaction and to tackling climate change through reductions in carbon emissions.

Guidance in rethinking how we provide for all movement is covered in more detail in Chapters G3 and G4.

ACCESS

1.3.5 Providing frontages that are directly accessible on foot and that are overlooked from the street is highly desirable in most circumstances as this helps to ensure that streets are lively and active places.

1.3.6 Access to buildings and public spaces is another important function of streets. Pedestrian access should be designed for people of all ages and abilities.

1.3.7 Guidance for providing access is given in Chapters G3 and G4.

PARKING

1.3.8 Parking is a key function of many streets. A well-designed arrangement of on-street parking provides convenient access to frontages and can add to the vitality of a street. Conversely, poorly designed parking can create safety problems and reduce the visual quality of a street. Generally a variety of solutions will be required.

1.3.9 Guidance for parking is covered in more detail in Chapter G5.

DRAINING, UTILITIES AND STREET LIGHTING

1.3.10 Streets are the main conduits for drainage and utilities. Buried services can have a major impact on the design and maintenance requirements of streets. Surface water management including sustainable drainage systems bring environmental benefits, such as flood control, creating wildlife habitats and efficient wastewater recycling. Well designed street lighting needs to take account of the local context as well as function. Drainage and utilities are covered in Chapter G6, and street lighting is covered in Chapter G8.

1.4 THE BALANCE BETWEEN SPACE AND MOVEMENT

1.4.1 Of the five functions, place and movement are the most important in determining the character of streets.

1.4.2 In the past, road design hierarchies have been based almost exclusively on the importance attributed to vehicular movement. This has led to the marginalisation of pedestrians and cyclists in the upper tiers where vehicular capacity requirements predominate. The principle that a road was primarily for motor traffic has tended to filter down into the design of streets in the bottom tiers of the hierarchy.

1.4.3 This approach has created disjointed patterns of development. High-speed roads often have poor provision for pedestrian activity, cutting residential areas off from each other and from other parts of a settlement. In addition, the hierarchy does not allow for busy mixed use arterial streets, which feature in most traditional towns and cities.

1.4.4 Streets should no longer be designed by assuming 'place' to be automatically subservient to 'movement'. Both should be considered in combination, with their relative importance depending on the street's function within a network, with their relative importance depending on the street's function within a network and often varying along their length and at different times of the day. It is only by considering both aspects that the right balance will be achieved. Away from motorways and some other inter-urban trunk roads it is seldom appropriate to focus solely on one to the exclusion of the other, even in streets carrying heavier volumes of traffic, such as high streets.

1.4.5 Place status denotes the relative significance of a street, junction or section of a street in human terms. The most important places will usually be near the centre of any settlement or built-up area, but important places will also exist along arterial routes, in district centres, local centres and within neighbourhoods.

1.4.6 Locations with a relatively high place function would be those where people are likely to gather and interact with each other, such as outside schools, in local town and district centres or near shops. Streets that pass through these areas need to reflect the importance of these places in their design.

1.4.7 Movement status can be expressed in terms of traffic volume and the importance of the street, or section of street, within a network either for general traffic or within a mode specific (e.g. bus or cycle) network. It can vary along the length of a route, such as where a trunk road passes through a town centre.

1.4.8 Road authorities assess the relative importance of particular routes within an urban area as part of their normal responsibilities, such as those under the New Roads and Streetworks Act 1991⁴.

1.4.9 Another way of assessing the movement status of a street is to consider the geographical scale of the destinations it serves. Here, movement status can range from national networks (including motorways) through to city, town, district, neighbourhood and local networks, where the movement function of motor vehicles is slightly lower.

PLACE AND MOVEMENT MATRIX

1.4.10 Defining the relative importance of particular streets/roads in terms of place and movement functions should inform subsequent design choices. For example:

• motorways - high movement function, low place function;
• high streets - medium movement function, medium to high place function; and
• residential streets - low to medium movement function, low to medium place function.

1.4.11 This way of looking at streets can be expressed as a two-dimensional hierarchy ⁵ where the axes are defined in terms of place and movement (Fig.1.3). It recognises that, whilst some streets are more important than others in terms of traffic flow, some are also more important than others in terms of their place function and deserve to be treated differently. This approach allows designers to break away from previous approaches to hierarchy, whereby street designs were only based on traffic considerations.

Figure 1.3 Typical road and street types in the Place and Movement hierarchy.

1.4.12 Once the relative significance of the movement and place functions has been established, it is possible to set objectives for particular parts of a network. This will allow the local authority to select appropriate design criteria for creating new links or for changing existing ones.

1.4.13 Movement and place considerations are important in determining the appropriate design speeds, speed limits and road geometry, etc., along with the level of adjacent development and traffic composition.

1.4.14 The detailed guidance contained in Designing Streets concentrates on streets with a fairly low movement function, in particular residential streets. However, many of the design principles also have application on streets with a higher movement function and corresponding place function (Fig 1.4).

Figure 1.4 Melrose town centre, an example of streets with a high movement function which in light of a recent innovative design approach retains a high place and movement function (Scottish Borders Council).

1.5 POLICY, LEGAL AND TECHNICAL CONTEXT

1.5.1 There is a complex set of legislation, polices and guidance applying to the design of streets. There is a tendency among some designers and approving authorities to treat design guidance as hard and fast rules because of the mistaken assumption that to do otherwise would be illegal or counter to a stringent policy. This approach is wrong. It restricts innovation, and leads to standardised streets with little sense of place or quality. In fact there is considerable scope for designers and approving authorities to adopt a more flexible approach on many issues. It is therefore Government policy in Designing Places to encourage street design which engenders place and quality.

1.5.2 By copying a standard example without due consideration, designers surrender their own professionalism. When doing so, they still retain responsibility for the design as it is their decision to copy a standard example which has been produced by individuals who may never have seen the site in question, and which may therefore not be suitable.

1.5.3 The following comprise the various tiers of instruction and advice:

• the legal framework of statutes, regulations and case law;
• government policy;
• government guidance;
• local policies;
• local guidance;
• design standards; and
• evidence and research base and the concept of "evidence-based design".

1.5.4 The Westminster and Scottish Parliaments and the Courts have established the legal framework. In this respect certain aspects of transport are reserved to Westminster in terms of the Scotland Act 1998. For example, this includes the provisions which are the subject matter of the Road Traffic Act 1988, namely traffic signs and speed limits.

1.5.5 The Scottish Government develops policies aimed at meeting various objectives which roads and planning authorities are directed to follow. Designing Places and Designing Streets are such policies. It also issues supporting guidance to help authorities implement these policies, including the chapters G1 to G8 of Designing Streets.

1.5.6 Evidence based design has been developed as a concept within recent years. A distinction needs to be drawn between policies, guidance and practices that are in essence rule of thumb and that reflect simply a continuation of a conventional approach, and those that are based on science, statistics and designed experimental studies, and regularly challenged to ensure that they are relevant to modern needs and conditions. Designing Streets is supported by an evidence base.

1.5.7 Within this overall framework, road and planning authorities have considerable leeway to develop local policies and standards, and to make technical judgements with regard to how they are applied. Other bodies also produce advisory and research material that they can draw on.

1.6 RISK AND LIABILITY

1.6.1 A major concern expressed by some road authorities when considering more innovative designs, or designs that are at variance with established practice, is whether they would incur a liability in the event of damage or injury.

1.6.2 This can lead to an over-cautious approach, where designers strictly comply with guidance regardless of its suitability, and to the detriment of innovation. This is not conducive to creating distinctive places that help to support thriving communities.

1.6.3 In fact, imaginative and context-specific design that does not rely on conventional standards can achieve high levels of safety. The design of Poundbury in Dorset, for example, did not comply fully with standards and guidance then extant, yet it has few reported accidents. This issue was explored in some detail in the publication Highway Risk and Liability Claims⁶.

1.6.4 Claims against road authorities relate almost exclusively to alleged deficiencies in maintenance. Claims for design faults are extremely rare. The duty of the road authority to maintain the road is set out in the Roads (Scotland) Act 1984⁷, and case law has clarified the law in this area.

1.6.5 The courts in Scotland have adopted a cautious approach when considering the duty of care potentially owed by roads authorities. Merely because a roads authority has powers does not generally open up the authority to liability. The circumstances in which roads authorities have been held liable in damages have been very restricted. The restrictive approach has also been adopted in circumstances where the risk of an accident may well be foreseeable. (See Murray v Nicholls⁸ and Bennett v J Lamont & Sons)⁹

1.6.6 The Scottish line of authority has been recently reinforced by the House of Lords in the case of Gorringe v. Calderdale MBC (2004). ¹⁰ A claim was made against a highway authority in England for failing to maintain a ' SLOW' marking on the approach to a sharp crest. The judgement confirmed a number of important points:

• the authority's duty to 'maintain' covers the fabric of a highway, but not signs and markings;
• there is no requirement for the road authority to 'give warning of obvious dangers' and natural road hazards; and
• drivers are 'first and foremost responsible for their own safety'.

1.6.7 A handful of claims for negligence and/or failure to carry out a statutory duty have been made under section 39 of the Road Traffic Act 1988¹¹, which places a general duty on road authorities to promote road safety. In connection with new roads, section 39 (3)(c) states that road authorities 'in constructing new roads, must take such measures as appear to the authority to be appropriate to reduce the possibilities of such accidents when the roads come into use'.

1.6.8 The Gorringe v.Calderdale judgment made it clear that section 39 of the Road Traffic Act 1988 did not create a duty of care and, therefore, does not form the basis for a liability claim.

1.6.9 Advice to road authorities on managing their risks associated with new designs is given in Chapter 5 of Highway Risk and Liability Claims. In summary, this advises that authorities should put procedures in place that allow rational decisions to be made with the minimum of bureaucracy, and that create an audit trail that could subsequently be used as evidence in court.

1.6.10 Suggested procedures (which accord with those set out in Chapter 3 of Designing Streets) include the following key steps:

• set clear and concise scheme objectives;
• work up the design against these objectives; and
• review the design against these objectives through a quality audit

1.7 B ALANCED DECISIONS

A suggested framework from Highway Risk and Liability Claims (2008) which accords with those set out in Designing Streets is:-

Vision - there should be an overall vision for an area, that reflects local and national policy and where appropriate, the views of the local community

Objectives / Purpose. There should be a robust understanding of what the scheme is intended to do. This will normally include balancing:

• Movement and Place
• Risk and Opportunity
• Ensuring sustainability

Design - this should be worked up against the objectives

Quality audit - this is a review of the design against the objectives set.

1.8 DISABILITY DISCRIMINATION

1.8.1 Road and planning authorities must comply with the Disability Equality Duty under the Disability Discrimination Act 2005¹². This means that in their decisions and actions, authorities are required to have due regard to the six principles of:

• promote equality of opportunity between disabled persons and other persons;
• eliminate discrimination that is unlawful under the 2005 Act;
• eliminate harassment of disabled persons that is related to their disabilities;
• promote positive attitudes towards disabled persons;
• encourage participation by disabled persons in public life; and
• take steps to take account of disabled persons' disabilities, even where that involves treating disabled persons more favourably than other persons.

1.8.2 Those who fail to observe these requirements will be at the risk of a claim. Not only is there an expectation of positive action, but the duty is retrospective and local authorities will be expected to take reasonable action to rectify occurrences of non-compliance in existing areas.

1.8.3 The Disability Rights Commission ( DRC) have published a Statutory Code of Practice on the Disability Equality Duty¹³ and they have also published specific guidance for those dealing with planning, buildings and the street environment.

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