Design manual
Design Manual for Urban Roads and Streets
The design of roads and streets within urban speed limits.
Department of Transport, Tourism and Sport and Department of Housing, Planning and Local Government · 2019 (version 1.1) · 165 pages
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- 89May 2019 (Version 1.1) 4.3.2 Pedestrian Crossings Crossings are one of the most important aspects of street design as it is at this location that most interactions between pedestrians, cyclists and motor vehicles occur. Well designed and frequently provided crossings are critical to the balancing of movement priorities. The design of crossings, and the frequency at which they are provided, will have a significant impact on pedestrian/ cyclist mobility and comfort and the flow of vehicular traffic. Crossing Selection Crossings are referred to as controlled, such as zebra or signalised crossings or uncontrolled.21 Uncontrolled crossings include less formal types such as courtesy crossings and/or those identified by a drop kerb. At junction locations the type of crossing used will generally be determined in conjunction with the form of junction control that is used to manage traffic (see Section 4.4.3 Junction Design). More generally, designers should be guided by pedestrian demands, safety and vehicle flows. In this regard: • In general, signalised crossings should be provided on busy Arterial and Link streets and/or where cyclists are likely to cross. 21 Refer to Section 12.3-12.4 of the Traffic Management Guidelines (2003). • Zebra crossings provide pedestrian priority and may be used where formal crossing facilities are desirable, however a fully signalised crossing is not needed. Examples may include on Arterial and Link streets within lower speed environments, such as Centres (see Figure 4.37) and/ or where both levels of pedestrian and vehicular activity are more moderate.22 • Courtesy crossings, which are generally defined by a change in material and/ or vertical deflection (see Section 4.4.7 Horizontal and Vertical Deflections), allow pedestrians to informally assert a degree of priority over drivers. They may be used in lower speed environments where formal crossing facilities are not required to assist in making such environments self regulating, see Figure 4.38. • Local streets, due to their lightly-trafficked/ low-speed nature, generally do not require the provision of controlled crossings. The provision of drop kerbs will generally suffice. However zebra crossings or courtesy crossing should be considered where pedestrian demands are higher such as around Focal Points. 22 Refer to Section 12.3 of the Traffic Management Guidelines (2003). Figure 4.38: Example of an informal ‘courtesy’ crossing in Westport, Co. Mayo. Drivers stop and wait for pedestrians to cross as a courtesy. Figure 4.37: Example of a Zebra crossing within the town centre of Dundalk, Co. Louth. Zebra crossings promote greater levels of pedestrian priority as drivers must give way to pedestrians once they have commenced the crossing.
- Design Manual for Urban Roads and Streets90 Figure 4.39: Example of a wide streets with a crossing that allows pedestrians to cross in a direct manner and in a single movement. The median acts as a refuge island for those users who cannot cross the street in a reasonable time. Crossing Design and Waiting Times Smarter Travel (2009) requires that pedestrian movement at signalised crossings be given priority by timing traffic signals to favour pedestrians instead of vehicles by reducing pedestrian waiting times and crossing distances at junctions.23 To achieve this objective, designers should: • Optimise pedestrian movement, with pedestrian cycle times of no more than 90 seconds at traffic signals. • Allow pedestrians to cross the street in a single, direct movement (see Figure 4.39). Staggered/staged crossings should not be used where pedestrians are active, such as in Centres, Neighbourhoods and Suburbs (except where stated below). • Where staggered/staged crossings currently exist they should be removed as part of any major upgrade works. This should include realignment works to slow vehicle movements, such as reduced corner radii and/or carriageway narrowing (see Figure 4.40 and Section 4.3.3 Corner Radii) 23 Refer to Action 16 of Smarter Travel (2009). Crossing Locations The location and frequency of crossings should align with key desire lines and be provided at regular intervals. Within larger areas this may need to be addressed via a spatial analysis and supporting plan (see also Section 5.2.1 Plans and Policies). Methods that rely on absolute figures, such as the system of warrants, should not be used. More generally, designers should: • Provide pedestrian crossing facilities at junctions and on each arm of the junction. • Minimise corner radii so that crossing points are located closer to corners on pedestrian desire lines (see Section 4.3.3 Corner Radii). • Provide regular mid block crossings in areas of higher pedestrian activity, such as Centres, where the distance between junctions is greater than 120m. • Locate mid-block crossings at strategic locations where pedestrians are likely to cross, such as adjacent to bus stops and Focal Points, or to coincide with trafficcalming measures on longer straights (see Section 4.4.7 Horizontal and Vertical Deflections).
- 91May 2019 (Version 1.1) Designers may have concerns regarding the omission of staggered/staged crossings on wide streets (i.e. with four or more lanes and a median) on the grounds of safety and traffic flow. With regard to safety these concerns may be overcome by: • Ensuring enough green time is provided for pedestrians to cross in a single movement. • Removing flashing amber lights phases where vehicles may move forward not realising pedestrians are still on the median or far side of the crossing. • Providing build-outs, where possible, to reduce the crossing distance. • Providing a refuge island (minimum of 2m) for those who are unable to make it all the way across in a reasonable time. Under such circumstances a Push Button Unit (PBU) and the required signals must be provided within the refuge. Safety concerns regarding pedestrian crossings should also be viewed in the context of pedestrian behaviour. Research has found that pedestrians are less likely to comply with the detour/delay created by staggered crossings, leading to unsafe crossing behaviour.24 It will generally be more desirable, from a safety point of view, to provide a direct single phase crossing. 24 Refer to Pedestrian Crossing Behaviour at Signalised Crossings (2008). With regard to traffic flow on wide streets a more flexible approach may be taken where traffic modelling confirms that junctions would become overly saturated for long periods if designed with single phase/direct pedestrian crossings. A judgement will need to be made as there may be circumstances where it is acceptable to saturate junctions in order to prioritise/promote more sustainable travel patterns (see Section 3.4.2 Traffic Congestion) In these circumstances designers may also consider: • A straight ahead two stage crossing within lower speed environments where the median is sufficiently wide to clearly distinguish each arm of the crossing. • Increase pedestrian cycle times up to 120 seconds for short or intermittent periods (i.e. when saturation is likely to occur). • Implement more conventional staggered crossings where the balance of place and movement is weighted toward vehicle movement such as on Arterial streets in Suburban areas or more broadly in Industrial Estates and the Rural Fringe. Where applied, the width of the central area for pedestrian circulation should be a minimum of 2m. Figure 4.40: Example from Kensington High Street, London, of a left hand turning slip point was removed and replaced with a safer single phase crossing which also slowed vehicle turning movements (image source: Hamilton Baillie). BEFORE AFTER
- Design Manual for Urban Roads and Streets92 When determining the width of crossings designers should refer to Section 7.16 of the Traffic Signs Manual (2010) which contains maximum and minimum design specifications for pedestrian crossings. In this regard (see Figure 4.41):25 • Within Centres and on Arterial streets, all crossings should generally be a minimum of 4m wide. • The minimum width of all other pedestrian crossings should be 2m. • The minimum width for Toucan crossings should be 4m. • In determining the optimal width of a pedestrian crossing, designers may refer to Figure 4.34 to ensure that pedestrians are able to pass each other in comfort. • On crossings where very high numbers of pedestrians and/or cyclists cross, a width in excess of those above may be required, to a maximum of 10m. It is also an objective of Smarter Travel (2009) that level grade crossings (i.e. those that are aligned with the height of footways) be provided for pedestrians across junctions.26 These are highly recommended in areas where pedestrian flows are high such as in Centres. They are also an effective measure for calming traffic and enforcing lower speeds (See Section 4.4.7 Horizontal and Vertical Deflections). 25 Refer to Section 7.16 of the Traffic Signs Manual (2010) which contains maximum and minimum design specifications for pedestrian crossings. 26 Refer to Action 16 of Smarter Travel (2009). Figure 4.41: Standard crossing widths to be used in most circumstances across the main carriageway of Access or Link streets and across side junctions with Local streets. Min 4.0m Min 2-3m
- 93May 2019 (Version 1.1) 4.3.3 Corner Radii Reducing corner radii will significantly improve pedestrian and cyclist safety at junctions by lowering the speed at which vehicles can turn corners and by increasing inter-visibility between users (see Figure 4.42). Reduced corner radii also assist in the creation of more compact junctions that also align crossing points with desire lines and reduce crossing distances. Corner radius is often determined by swept path analysis. Whilst swept path analysis should be taken into account, designers need to be cautious as the analysis may over estimate the amount of space needed and/ or the speed at which the corner is taken. Furthermore, such analysis also tends to cater for the large vehicles which may only account for relatively few movements. Figure 4.42: Illustration of the benefits of reduced corner radii on pedestrian and cyclist safety (images based on Figures 6.3 and 6.15 of the UK Manual for Streets (2007)). Faster moving vehicle at edge of/ outside of pedestrians peripheral vision. Slower moving vehicle within pedestrians peripheral vision. Reduced crossing distance. Vehicle and cyclist speed is more compatible. Increased danger from faster moving vehicle cutting across cyclist. LARGER CORNER RADII REDUCED CORNER RADII Designers must balance the size of corner radii with user needs, pedestrian safety and the promotion of lower operating speeds. In this regard designers must consider the frequency with which larger vehicles are to be facilitated as follows (see Figure 4.43): • In general, on junctions between Arterial and/or Link streets a maximum corner radii of 6m should be applied. 6m will generally allow larger vehicles, such as buses and rigid body trucks, to turn corners without crossing the centre line of the intersecting road.27 27 Refer to Sections 6.9, 9.3 and 10.4 of the Traffic Management Guidelines (2003).
- Design Manual for Urban Roads and Streets94 • Where turning movements occur from an Arterial or Link street into a Local street corner radii may be reduced to 4.5m. • Where design speeds are low and movements by larger vehicles are infrequent, such as on Local streets, a maximum corner radii of 1-3m should be applied. • In circumstances where there are regular turning movements by articulated vehicles, the corner radii may be increased to 9m (i.e. such as in Industrial Estates). Designers may have concerns regarding larger vehicles crossing the centre line of the intersecting street or road. Such manoeuvres are acceptable when turning into/or between Local or lightly trafficked Link streets as keeping vehicle speeds low is of higher priority. Where designers find it difficult to apply the radii referred to above, or to further reduce corner radii where pedestrian activity is high (such as within centres) designers may also: • Increase the carriageway width at junctions to provide additional manoeuvrability without signalling to drivers that the corner can be taken at greater speeds (see Figure 4.44). X X+ Figure 4.44: Illustration of how tighter corner radii can be applied to a junction, with additional manoeuvrability for larger vehicles provided by widening the street entrance. Figure 4.43: Approaches minimising corner radii according to level of service by larger vehicles. Few larger vehicles 1-3m Frequent larger vehicles 9m Occasional larger vehicles 4.5-6m CORNER RADII
- 95May 2019 (Version 1.1) • Apply setback vehicular stop lines at signalised junctions to allow turning vehicles to cross the centre line of the intersecting street without conflicting with oncoming movements (see Figure 4.45 and Section 4.4.2 of the National Cycle Manual (2011)). • Designers should also consider the use of setback stop lines on Arterial and Links streets within centres to further reduce corner radii. • Keeping corners clear of obstacles (or removing obstacles such as guardrails) to allow emergency vehicle overrun. Figure 4.45: Setback stop lines allow for additional vehicular manoeuvrability for larger vehicles at signalised junctions without the need for larger corner radii.
- Design Manual for Urban Roads and Streets96 4.3.4 Pedestrianised and Shared Surfaces Pedestrianised and shared surfaces are an effective way of promoting place and providing pedestrians and cyclists with a more enjoyable experience, particularly in areas of historic significance. These streets operate as linear ‘squares’ or corridors of public open space. Pedestrianised streets fully segregate pedestrians and cyclists from motor vehicular movement (although emergency access is possible and limited access may also be provided for service vehicles). They are generally only appropriate in areas where higher levels of activity can be sustained throughout the day and into the evening period, as the removal of vehicular traffic will reduce surveillance levels. They are best suited to the Centres around areas of retail, commercial and cultural activity (see Figure 4.46). Shared surface streets and junctions are integrated spaces where pedestrians, cyclists and vehicles share the main carriageway. This may include streets where the entire street reserve is shared (see Figure 4.47) or where designated sections may provide for pedestrians and/or cyclists use only with a shared surface carriageway along part of the street (see Figure 4.48). Shared surface streets may also periodically transfer from pedestrian only spaces to shared spaces at different times of the day (as per Figure 4.47). Shared surface streets and junctions are particularly effective at calming traffic. Research has found that shared carriageways perform well in terms of safety and there is also evidence to suggest that well designed schemes in appropriate settings can bring benefits in terms of visual amenity, economic performance and perceptions of personal safety.28 Shared surface streets and junctions are highly desirable where: • Movement priorities are low and there is a high place value in promoting more livable streets (i.e. homezones), such as on Local streets within Neighbourhood and Suburbs. 28 Refer to UK Department for Transport Shared Space Project Stage 1: Appraisal of Shared Space (2009). Figure 4.46: Fully pedestrianised street within a Centre. Activity is sustained by a mix of retail, commercial and cultural activities. Figure 4.48: Exhibition Road, London, an example where distinct zones that delineate pedestrian only space from shared space have been created (image source architects). Pedestrian Only Zone Shared Zone Figure 4.47: Street in Waterford City Centre which changes from a pedestrianised space to a shared surface area at different times of the day.
- 97May 2019 (Version 1.1) • Pedestrian activities are high and vehicle movements are only required for lowerlevel access or circulatory purposes. This include streets within Centres where a shared surface may be preferable over full pedestrianisation to ensure sufficient activity occurs during the daytime and the evening period. The application of shared surfaces may also be desirable on a wide variety of streets and junctions. The implementation of shared surfaces in the UK and internationally has evolved from lightly-trafficked areas to include heavily-trafficked streets and junctions (as per Figure 4.48 and Figure 4.49). Where designers consider the use of shared surfaces on more heavily-trafficked routes the location must be the subject of a rigorous analysis that assesses the suitability of a street for such purposes. The key condition for the design of any shared surface is that drivers, upon entering the street, recognise that they are in a shared space and react by driving very slowly (i.e. 20km/h or less). To ensure this, designers should: • Use a variety of materials and finishes that indicate that the carriageway is an extension of the pedestrian domain (such as paving: see Section 4.2.6 - Materials and Finishes). Figure 4.49: Shared surface junction in Ashford, Kent, UK, carries significant amounts of traffic and challenged conventions regarding traffic volumes along shared surfaces. An informal zebra crossing has also been marked adjacent to the junction to provide a place for less confident pedestrians to cross. • Avoid raised kerb lines. Any kerb line should be fully embedded within the street surface (see Section 4.4.8 Kerbs). • Minimise the width of the vehicular carriageway and/or corner radii (see Sections 4.3.3 Corner Radii and 4.4.1 Carriageway Widths). Shared surface streets can be very intimidating for impaired users. Visually-impaired users in particular usually rely on kerb lines to navigate streets. To assist navigation and movement through shared spaces, designers should apply design measures such as: • Sections of tactile paving that direct movement along the street or across spaces (see Figure 4.50). • The creation of distinct zones that delineate pedestrian only space from shared space (as per Figure 4.48). • Flush kerbs, drainage lines and/or sections of tactile paving to assist guide dogs and indicate movement from a pedestrian only space to a shared carriageway (see Section 4.4.8 Kerbs).
- Design Manual for Urban Roads and Streets98 Figure 4.51: Examples from Adamstown, Co. Dublin, where a verge is provided as refuge that pedestrians can hop on and hop off as cars slowly pass. • Verges that act as refuge zones allowing pedestrians to step on and off the carriageway to let cars pass (see Figure 4.51). Figure 4.50: Examples from Cork city of the use of tactile paving that assist the visually impaired by guiding movement across a shared space.
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