BEST PRACTICES IN INFRASTRUCTURE DESIGN FOR SUSTAINABLE SAFETY PROF. DR. MARTIN VAN MAARSEVEEN

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1 BEST PRACTICES IN INFRASTRUCTURE DESIGN FOR SUSTAINABLE SAFETY PROF. DR. MARTIN VAN MAARSEVEEN

2 OBJECTIVES OF THIS LECTURE After this lecture participants should be able to: Understand the aims, approach and principles of the Sustainable Safety vision Understand the need for hierarchy in road networks, based on the functionality of each road in the network Recognize the various design solutions for NMT from a sustainably safe perspective, and to be able to identify which solutions are to be preferred in diffent situations Have insight in best practices in safe design for NMT facilities Organization: Lecture

3 VULNERABLE ROAD USERS Pedestrians and cyclists are vulnerable road users. Safety is at the heart of all good design. The designer should ensure that the principles of Sustainable Safety have been applied to all schemes. The principles of Sustainable Safety were developed in 1992, and in the following years in the Netherlands. They underpin all road design and the adherence to those principles has contributed to the Netherlands leading record in road safety. Sustainable means: we don t want to hand over a road traffic system to our children in which the same number of people will be injured or killed as is today.

4 SUSTAINABLE SAFETY The aims of the vision Sustainable Safety are: Preventing (serious) crashes, simply by eliminating conditions and circumstances where crashes can occur Reducing the probability of severe injury, when crashes cannot be prevented Source:

5 GENERAL APPROACH User-oriented system approach Man is the measure of all things, i.e. humans are vulnerable, are error prone, and do not always obey rules Proactive approach Preventing system gaps, i.e. intervening in the chain of system design to human behaviour as early as possible Source: SWOV, 2006

6 INTEGRAL (HOLISTIC) APPROACH Infrastructure Tuned to road users capabilities and limitations Vehicle Simplify driving task Provide protection Holistic Human Human Well-instructed Well-informed Vehicle Infrastructure Regina Orvaňanos Murguía

7 3 E s Sustainable safety is about: ENGINEERING ENFORCEMENT EDUCATION However, in this lecture we will focus on the engineering aspect only!

8 GUIDING PRINCIPLES In order to achieve a sustainably safe road traffic, 5 guiding principles have been drawn up, that are all based on scientific theories and research: Source: SWOV, 2006

9 FUNCTIONALITY Traffic has two functions: to flow and to exchange. These are very different functions, and they each require a specific infrastructure and specific use requirements to make safe traffic distribution possible. Based on this traffic engineering distinction and inspired by the functional categorization of roads (Buchanan, 1963), roads ideally fulfil just one single function: monofunctionality. To flow To exchange Source: SWOV, 2012

10 FUNCTIONAL ROAD CATEGORIZATION Through roads Traffic should flow SWOV, 2012 Distributor roads Flow function on road sections Exchange of traffic at intersections Access roads Residence and exchange of traffic is central

11 HOMOGENEITY There where road users/vehicles with large mass differences use the same traffic space, the speeds should be so low that the most vulnerable road users and transport modes come out of a crash without any severe injuries. At locations where traffic uses high speeds, different types of road user and road users driving in different directions should be physically separated from each other as much as possible. That way, conflicts leading to severe injury are prevented. Source: SWOV, 2012

12 PREDICTABILITY A predictable layout of a road prevents unsafe actions in traffic as much as possible because it allows road users to better know what to expect (types of road users, manoeuvres, road course) and what will be expected of them (speed, manoeuvres). A predictable layout of roads helps to predict the traffic situation; this is of vital importance, especially when high speeds are involved. Predictable? Source: SWOV, 2012

13 FORGIVINGNESS Forgiving surroundings ensure that the physical consequences of errors remain limited. In the elaboration of this principle, one could, for example, think of safe shoulders, obstacle-free zones, or collision-friendly obstacle protection. Social forgivingness refers to the role of road users in preventing crashes: The willingness to anticipate a potentially unsafe action of another road user, and to act in such a manner that negative consequences of this potentially unsafe action are prevented or in any case limited Source: SWOV, 2012

14 STATE AWARENESS The principle of state awareness involves a road user being capable of assessing his own task capability well. The task requirements (road condition, weather condition, vehicle condition and the condition of other road users) determine what is needed to perform the traffic task well. The task competence of the traffic participant is determined by his competences (more or less static skills), and physical and psychological situations (stress, fatigue, alcohol and such). Source: SWOV, 2012

15 APPLICATION IN INFRASTRUCTURE DESIGN In the urban network create a limited number of road categories with each a specific function, and a consistent road design to envisage use. Create consistency between function, shape and use

16 HIERARCHY OF THE ROAD NETWORK Access roads Distributor roads Through roads Roads, often with parking allowed, providing access to primarily residential areas and/or primarily pedestrian commercial zones in central business districts. These roads connect and serve residential (habitat) areas. Roads meant to collect and distribute motorized traffic coming from and going to habitat areas or other destinations. Such roads sometimes take the form of a circular road around a habitat area. Accommodate both motorized and non-motorized transport. Roads consist of major road infrastructure that gives priority to cars. They usually also serve trucks and other forms of transport, and they may incorporate special lanes for buses. They seek to minimize delays and therefore typically rely on underpasses and overpasses

17 PHILOSOPHY Road hierarchy, route choice and road safety Through roads Distributor roads Access roads From origin to destination A motorized trip starts at a low hierarchy, then as soon as possible continues to a higher or the highest hierarchy, where the largest portion of the trip takes place, then as close as possible to the destination steps down to the lower hierarchies to end at the destination.

18 TYPES OF INTERVENTIONS

19 SOCIAL FUNCTION VERSUS TRAFFIC FUNCTION Traffic function Social function Access roads Distributor roads Through roads

20 SOCIAL FUNCTION AND/OR TRAFFIC FUNCTION Access roads Distributor roads Priority must go to social life Mix of different uses and purposes Motorized traffic can be allowed, as long as it plays a subordinate role Relatively fast-flowing traffic may occupy one or two lanes in each direction, with adequate sidewalks for pedestrians and cycle lanes, preferably separated by a median from motorized traffic. Through roads Priority goes to the smooth flow of motorized traffic This means not only limitations in terms of requirements of drivers and vehicles, but also homogenizing the flow of motor vehicles in direction and speed

21 EXAMPLE: ACCESS ROAD

22 EXAMPLE: DISTRIBUTOR ROAD Regina Orvaňanos Murguía

23 EXAMPLE: THROUGH ROAD

24 VARIATION VERSUS UNIFORMITY Uniformity Variation Access road Distributor road Through road

25 VARIATION A varied streetscape attracts attention, by reinforcing the sense that something may pop up anytime, anywhere. Moreover, it offers extra possibilities to adapt public space to local needs and create an attractive environment. This is especially important in residential areas, where social life, walking and cycling should take priority.

26 UNIFORMITY Uniformity in road design and traffic signs offers the advantage of making these readily recognized and understood. Users require less time to respond to changes in conditions. This is especially important in situations where there is little time to react because of high traffic volumes, but also when a collision may have a relatively severe impact, because of large differences in speed, direction, mass, and vulnerability, making it especially important to protect different kinds of vehicles and road users

27 CHAIN OF RECOGNIZABLE LAY-OUT AND PREDICTABLE BEHAVIOUR Source: SWOV, 2010

28 RECOGNIZABITY CHARACTERISTICS 1. type of road surface 2. design of the driving direction separation (axis markings or physical separation) 3. edge marking 4. (anti) flow marking 5. salient colour and shape of kerb marker posts 6. urban road characteristics such as buildings, parking spaces and exit roads 7. (red) recommended cycle lanes on the carriageway Source: SWOV, 2010

29 EXAMPLE: Essential Recognizability Characteristics in the Netherlands

30 INTEGRATION VERSUS SEGREGATION Segregation Integration Access road Distributor road Through road

31 INTEGRATION VERSUS SEGREGATION One major decision involves the question of how integrated or segregated the different modes non-motorized or motorized should be: to what extent will specific space on the road and at intersections be assigned to each group or will they be sharing lanes and mingling at crossroads? In many situations, the speeds and volumes of motorized traffic, in combination with the distance to oncoming traffic, are incompatible with walking and cycling. This incompatibility increases the risks to cyclists and pedestrians, since safety correlates directly with the number of encounters and the complexity of traffic conditions. Large numbers of fast-moving cars also affect the quality of the ride for cyclists or walking conditions for pedestrians.

32 CONSIDERATIONS OF SEGREGATION Advantages are that road sections with segregated facilities protect pedestrians and cyclists better, drivers overtaking manoeuvres are easier, and cyclists are less affected by congestion. Moreover, walking and cycling becomes more comfortable as the need for alertness is decreased. These advantages may be lost, however, if good, NMTfriendly solutions cannot be included in intersections. Most NMT trips are short. Detours can therefore make NMT unattractive. This makes it very important to offer pedestrians and cyclists safe crossings at most side streets.

33 TYPES OF SEGREGATION: no segregation (unattractive)

34 TYPES OF SEGREGATION: no segregation (attractive)

35 TYPES OF SEGREGATION: visual segregation

36 TYPES OF SEGREGATION: physical segregation

37 TYPES OF SEGREGATION: complete segregation

38 GUIDELINES FOR SEGREGATION VERSUS INTEGRATION

39 FEASIBILITY OF WIDESCALE SEGREGATION It may not be feasible to re-engineer much of the existing urban space to provide for segregated facilities. Integrated cycling solutions, based on the hierarchy of provision, are likely to be more effective in terms of cost and delivery. However, integrated facilities are likely to require significant changes to the traffic regime. The transport implications of significant reductions in speed and volume of traffic on key arteries to and through cities and towns needs to fully understood and planned for, within the sustainable urban traffic plan, before embarking on such changes.

40 BEST PRACTICES: SUCCESS FACTORS Smart internal organisation Smart external organisation Integrated approach Keen problem analysis User involvement Linking to finances Societal support Political support Regional collaboration Project approach Source: Fietsberaad, 2013

41 BEST PRACTICES CONT D Success factor Practice Example Integrated approach Let the interest of NMT road safety coincide with other policy areas Installation/replacement sewer system, reconstruction for BRT system, reconstruction of intersection Keen problem analysis Linking to finances Political support Project approach What is the problem, who are affected, what aspects are important? Smart combination of financial sources and budgets Identify quick wins to support political reality Create project organisation (leader and team) Collect facts and figures, set up a strong argumentation indicating size and urgency of the problem Maintenance budgets, budgets for BRT infrastructure, (inter)national subsidies Link long term investments to ongoing projects, frame the intervention to political agendas, build on existing success stories Create commitment, make a strict planning, take care of adequate and timely communication

42 BEST PRACTICES CONT D Success factor Practice Example User involvement Societal support Regional collaboration The intervention should fit with needs and expectations of the target group Identify and involve stakeholders (private sector, CSO s) in a very early stage of the process Regional collaboration can boost internal decision-making processes Let users provide insight in the problem, stimulate them to suggest solutions, and set, if necessary, priorities Regular consultation, good communication, and representation in the media Link local policy to higher level policies, stimulate higher level agreement to simplify internal processes

43 FURTHER READINGS SWOV, Advancing Sustainable safety, SWOV Fact Sheet, Background of the five Sustainable Safety principles, round.pdf SWOV Fact Sheet, Recognizable road design, n.pdf