Urban Roads

Urban Roads

Key Facts:

  • The definition of urban roads used for national statistics is all major and minor roads within an urban area with a population of 10,000 or more (based on the 2001 Communities and Local Government definition of Urban Settlements). Rural roads are major and minor roads outside urban areas (DfT, 2013a). In 2015, 62% of all road accident casualties occurred on urban roads (RRCGB, DfT, 2016).

  • In 2015, 592 fatal and 11,611 serious road accidents were reported on urban roads. In terms of accident causation factors on urban roads, “failed to look properly” was reported as a contributory factor for 49% of accidents, compared with 34% of accidents on rural roads and 35% of accidents on motorways. Twenty one percent of fatal accidents on urban roads involved a pedestrian that failed to look properly and a further 11% involved a pedestrian that failed to judge a vehicle’s path or speed (RRCGB, DfT, 2016).

  • There is a wealth of literature covering the myriad issues that fall into the category of road safety on urban roads. There are a number of publications that are of particular relevance and provide a useful overview including the Department for Transport’s Manual for Streets (DfT, 2007) and the subsequent Manual for Streets 2 Wider Application of the Principles (CIHT, 2010). More recent publications have been produced by the CIHT to assist professionals in implementing the Manual for Streets guidance including: ‘Planning for Cycling’ (CIHT, 2014), ‘Involving the Public and Other Stakeholders’ (CIHT, 2015a), ‘Planning for Walking’ (CIHT, 2015b) and ‘Designing for Walking’ (2015c).

  • Previously, traditional approaches were focussed on segregation of road users to minimise interactions. New towns built in the 1950s and 60s typify this style of urban planning. An alternative approach, originating in the Netherlands, aims to achieve the complete opposite. The safety problems on urban roads stem from too many people trying to use the same space, causing problems for vulnerable road users; rather than segregating users, the concept of “shared space” aims to minimise demarcations between users, finding ways to reduce the dominance of motor vehicles and changing the way that the space operates. It is important to note however that poorly implemented shared space schemes can have adverse effects.

  • For shared space schemes, the aim is usually to achieve vehicle speeds of under 20mph, and preferably less than 15mph. Vehicle speed and flow have a significant impact on pedestrians’ willingness to share space and also drivers’ willingness to give way to other users. Available evidence shows comparable casualty levels for shared space versus conventional streets, despite shared space streets showing increased use by pedestrians and cyclists (DfT, 2011). However not all user groups are in favour of the shared space concept, and it is frequently opposed by organisations representing the blind, partially sighted and deaf. These users often express a strong preference for clear demarcation and separation, and can have difficulties resulting from the removal of familiar features such as kerbs and railings. Other studies (Moody & Melia, 2014) suggest that the claims made by shared space advocates have overstated the available evidence. They have concluded that some pedestrians, particularly the elderly, can feel intimidated by shared space and prefer conventional crossings, and that most pedestrians still give way to vehicles and feel less safe. Therefore, caution is required when proposing and implementing such schemes, particularly in environments of high traffic flows.

  • In recent years there has been considerable momentum towards the introduction of 20mph zones in urban environments. 20mph zones differ from shared space schemes in that they do not typically require extensive re-engineering of the road environment. For example, research has been conducted into the effectiveness of ‘sign-only’ 20mph schemes (e.g. Tapp & Toy, 2015a) in combination with materials produced to aid those interested in their implementation. The overall effect of 20mph zones on casualty reduction has been positive. For example, in London, it has been estimated that a reduction of 42% in killed or seriously injured causalities has been achieved in areas where 20mph zones have been implemented (Grundy et al., 2008).

  • The most vulnerable user group in the urban setting is pedestrians. On urban roads, pedestrians account for over a third of KSIs, with car occupants, motorcyclists and pedal cyclists each comprising roughly a fifth (RRCGB, DfT, 2016). Pedestrians and cyclists together account for a disproportionately high number of casualties in urban areas, whilst accounting for only a small percentage of the overall traffic. These figures serve to demonstrate that not only are pedestrians (and to a lesser extent cyclists) more at risk of an accident, they are also far more vulnerable to physical injury when accidents do occur. However these modes have health benefits that can outweigh this risk.

  • Innovation in cycling provision is a growth area and many road operators and authorities are looking to European best practice for inspiration. One example is hybrid cycle tracks which reallocate carriageway space for a cycle lane raised above carriageway surface, but below the footway. These are common in Copenhagen and other places on the continent (DfT, 2012). Transport for London carried out a major cycle safety research project looking at a range of junction layouts and traffic technology that are used in other countries, such as the use of ‘Dutch-style’ roundabouts and low-level cycle signals (TfL, 2013).

  • Even in situations where formal signal controlled crossings are required, there are measures that can be taken to improve facilities for pedestrians. For example, if there is an all-red phase during the signal cycle then diagonal crossing facilities can be provided, which are much quicker and more convenient for pedestrians (CIHT, 2010).

  • A great deal of information is available on the principles of traffic signal control (DfT, 2006) and the physical design of junctions and crossings to optimise safety (DfT, 2005a; DfT, 2005b).

  • Roundabouts have the lowest rate and lowest severity for motor vehicle collisions, but they have a poor record for cyclist safety and can also be a barrier to pedestrian movement. Slower speeds for vehicles, and hence increased safety for cyclists, can be encouraged through use of narrow exits and entries and small corner radii, resulting in more ‘continental-style’ compact roundabouts. Tight corner radii are also being used more and more at all junctions; this increases pedestrian and cyclist safety by reducing driver speed and increasing awareness (CIHT, 2010).

  • Keeping speeds low has been demonstrated to have significant safety benefits, particularly where space is shared between different user groups (CIHT, 2010).

  • Further information on all aspects of carriageway design and road geometry can be found in Design Manual for Roads and Bridges (DMRB, Highways Agency, 1993). (Note that all sections of DMRB are written specifically for trunk roads, and whilst relevant to urban roads, should not be applied uncritically.)

 

  • Date Added: 03 Apr 2012, 08:05 AM
  • Last Update: 30 Jan 2017, 01:59 PM