Evolvements of the Woonerf concept and design in urban planning Elvis Paja University IUAV of Venice Land Use and Transportation Planning Professor Reid Ewing December 7, 2015
Figure 1. The Methleys Home Zone, Leeds. Source B. Hamilton-Baillie, Towards shared space, Urban Design International, 2008, page 4
Abstract, what is a woonerf The idea for woonerfs, or “home zones”, was developed in the Netherlands during the 1960s. The idea behind woonerfs was to develop a street design integrating car traffic, pedestrians, cyclists, as well as children at play, within a commonly shared residential street space. The goal is to achieve a peaceful coexistence among all user types of urban residential streets. This objective is reached by getting away with the traditional separation of streets from sidewalks. Integrating all vehicular and pedestrian traffic into one living space simultaneously enhances safety and quality of life (International Home Zones 2004; WalkingInfo 2004; Biddulph 2001).
In a woonerf, the street is shared among pedestrians, bicyclists, and motor vehicles; however, pedestrians have priority over cars. The street is designed without a clear division between pedestrian and auto space (i.e., no continuous curb), so motorists are forced to slow down and travel with caution. Limiting vehicular speed not only improves residents’ feelings of safety, but also promotes greater use of the public space. This action allows more room for new features in the street such as street furniture (e.g., planters, street trees, benches) and areas for social interaction, bringing more people out on the streets to walk, bike, play, and interact with each other. In other words, a woonerf transforms the street into a livable and attracti1
Figure 2. Seven Dials, Covent Garden, London. Source B. Hamilton-Baillie, Towards shared space, Urban Design International, 2008, page 8.
ve environment for a variety of activities. The woonerf concept in urban planning has proven to be successful in the Netherlands. As a result, it has become increasingly popular in many other countries in Europe as well as around the world. (Appleyard and Cox 2006) The term itself, “woonerf,” varies from one country to another. For example, a woonerf is also known as a home zone. The home zone concept was developed from the woonerf concept in Britain in the late 1990s. According to Appleyard and Cox, there is a subtle difference between the two: a woonerf in the Netherlands emphasizes creating a sense of place, while a home zone in Britain focuses more on easing traffic and reducing accidents. However, both concepts incorporate formal and informal space for children’s play and social activities. Another concept is the shared street, which is commonly used in the United States; however, this concept can be applied to residential streets as well as commercial ones. Since all these terms, as well as others, originated from the woonerf concept, they share similar principles and design characteristics, and thus they are often used interchangeably.
Introduction, woonerfs, residential yards, and home zones: a first glimpse While the most common translation for woonerf into English is “home zone,” the literal translation 2
most likely would be “residential yard” (Hass-Klau 1990). Indeed, many home zone streets evoke the impression of a residential yard with trees, flowerbeds, benches, play areas, front gardens and other traffic-calming measures. Home zones make neighborhoods safer by allowing residents to reclaim their streets. They also create valuable living space and enhance the quality of life for everybody within the community (International Home Zones 2004; Biddulph 2001.). On the one hand, home zones allow residents to walk around freely and safely, socialize and pursue active lifestyles; on the other hand, they promote the idea of shared space and call for motor vehicle traffic to enter neighborhood streets as guests rather than as dominators of the space. In a home zone car speeds are very slow, often 10 mph or even “walking speed” (about 3 mph). Walking and cycling, as well as children playing outdoors, are integrated into one area similar to a big residential yard. Overall, home zones are used in an attempt to restore safety and a sense of “place” in neighborhoods that have become overwhelmed with automobile traffic (Hass-Klau 1990; International Home Zones 2004). The home zone concept can be applied not only when new neighborhoods are built, but also to retrofit existing roads into home zone streets (Children’s Play Council 2002). Due to the aesthetically enhanced environment and the resulting higher quality of life in home zone areas, the Dutch government has found that housing pri-
ces there are about 10 to 15 percent higher than on ordinary streets (Pharaoh and Russell 1991). The potential benefits of Home Zones are manifold and can be summarized as follows: × improved safety × higher property values × increased and wider ranging social activities and civic interaction × higher levels of accessibility for non-motorized modes of transport × less air and noise pollution × more efficient use of the street and urban living space. In a home zone, the formerly cardominated street scene becomes a more attractive, diverse, and livable environment (Hass-Klau 1990; Children’s Play Council 2004). There is also a range of negative opinions against the home zone concept. Some have merit and some are not supported by empirical evidence. These varied arguments include: × loss of parking × fear of accidents due to the mix of transportation modes × a potential for increased noise and air pollution (such as noise caused by driving over vertical traffic-calming devices or cobblestones) × air pollution resulting from frequent stopping and re-acceleration through trafficcalming devices (Voorhees 2004). After its development in the Netherlands, the home zone concept spread quickly across Europe, tailored to address conditions peculiar to each nation. In the next section case studies from the Netherlands, Germany, and the United Kingdom are presented. And some examples from Israel and the United States, that seems to have been slower in moving toward home zones, the idea has begun to take root, and some remarkable American adaptations of the woonerf follow the European examples.
Country-specific characteristics: case studies from the Netherlands, Germany, United Kingdom, Israel, and United States Home zones have existed in Europe for over 35 years. Many European countries, in fact, have established laws and regulations supporting home zone schemes. These laws have speed restrictions within home zones ranging from 20 to 10 mph and
Figure 3. Start of Home Zone and End of Home Zone. Source: IHIE, Home Zone Design Guidelines, 2002, page 19.
less. Many countries support the idea of assigning legal priority to pedestrians and cyclists, and within the home zone, motorists are presumptively responsible for accidents involving pedestrians and cyclists (European Commission 2004). In most European countries, home zones are used as part of a broader urban strategy to calm traffic and increase safety and livability, for example traffic calming schemes or safer routes to school programs (Hass-Klau 1990; Biddulph 2001; Hamilton-Baillie 2001). Indeed, it is important not to treat home zones as a single measure, but rather as part of a broader concept to reduce car traffic and enhance walking and cycling. The design of home zones all over Europe varies, but every country implementing these schemes has taken the core concepts and adapted them to its own particular social, economic, and juridical environment. By doing so, each nation has broadly achieved the same results: safer and more livable streets.
The Netherlands, Woonerven The original concept of the woonerf was developed and initiated in the late 1960s , in particular the citizens of Delft, Netherlands were at the forefront, where residents of a neighborhood were upset with cut-through traffic speeding through their neighborhood, making it unsafe; they took out their brick streets and replaced them with winding serpentine paths. This action initiated the woonerf, or “residential yard” in Dutch. According to Tolley (1990, chapter 4): Planners there began to ask why it was that their residential streets were so dull and so unsafe, and why was it impossible to do anything else there except drive cars - even though most of the time there were no moving cars. Traffic was 3
Figure 4. A cyclist on a woonerf in the Netherlands. Source: Burden, http://www.pedbikeimages.org.
seen as one of the greatest sources of blight, causing unsafety, discomfort and taking most of the space. Experiments with these new street designs, in which there was no segregation between motorized and nonmotorized traffic and in which pedestrians have priority in the whole street area, became Dutch law in 1976. In the 7 years after the new traffic law defining woonerven was passed a total of 2,700 such features (average size: two streets of approximately 200 meters (600 feet) in length) were built. The 1976 law lists some important characteristics of a woonerf that differentiate it from any other type of street. These include some very specific design requirements such as: × The impression that the highway is divided into a separate roadway for motor vehicles and a footpath must be avoided. There should, therefore, be no continuous difference in cross-sectional elements along the length of the road. × On those parts of the highway intended for motor vehicle use, features must be introduced which will restrict the speed of all types of vehicles. × These features should not be located so as to cause vehicles to pass too close to housing which fronts directly onto the road. × Adequate street lighting must be provided to e sure that all features, especially those referred to above, are fully visible at night (US Department of Transportation 1994). These main features, along with 10 others, were required in every woonerf. As a result, it was also felt necessary to publish a new set of traffic regulations especially for the woonerf. Five basic principles were outlined: × Pedestrians may use the full width of the roads 4
Figure 5. Woonerf, cul-de-sac in the Netherlands. Source: Dijkstra, VTC.
within a woonerf which is designated as such; playing is also permitted on the roadway. × Drivers within a woonerf may not drive faster than at walking pace. They must make allowance for the possible presence of pedestrians, including children at play, unmarked objects, and irregularities in the road surface, and the alignment of the roadway. × Traffic from the right has priority over traffic from the left in a woonerf. × Drivers may not hinder pedestrians within a woonerf. Pedestrians shall not unnecessarily hamper the progress of drivers in a woonerf. × Drivers of motor vehicles with more than two wheels are not permitted to park in a woonerf except at places which are identified by the appropriate traffic sign or the letter P marked on the pavement (US Department of Transportation 1994). The new Home Zone traffic sign was introduced with symbols of a house, playing child, pedestrian, and car. The biggest change, of course, was the notion that all road users should be integrated, not separated, for their mutual safety and benefit. The legal change was backed up with quite radical new street designs and layouts, and planners, engineers, and residents alike clamored for the introduction of woonerven. Drivers entering a woonerf must pass by a sign indicating the new rules that apply. No sidewalks are provided - the whole street is on the same level. Regular shifts in the vertical and horizontal alignment, street furniture, play areas, designated parking spots and different surface materials all contribute to the feeling that priority rests not with the motor vehicle, but with residents on foot, children playing, and nonmotorized users. Other important principles inherent in the original woonerf design included: × Woonerven were only appropriate for streets with an already low flow of through traffic. × Woonerven should always be two-way streets,
Figure 6. Shared space in Friesland, Netherlands. Source B. Juyoung Jung, Urban Streetscape, Delft University of Technology, 2013, page 53.
with passing places where necessary. × Access for emergency and service vehicles is always maintained. The widespread introduction of woonerven was closely evaluated: × Nationally, 70 percent of the Dutch population thought woonerven attractive or highly attractive. × Nonmotorized users assessed them more positively then motorized users. × Residents appreciated the low traffic volumes and absence of through traffic, but the bigger play areas and environmental improvements were even more of a benefit. × Injury accidents were reduced by 50 percent. × Vehicle speeds were reported to average 13-25 km/hour (8-15 mph) (US Department of Transportation 1994). As a result of this success, woonerven have become a routine feature of new residential area design. However, there have also been a number of problems identified with woonerven. Indeed, one problem experienced with their use was that residents living on the streets wholly inappropriate for implementation of a woonerven, pressured their governments to have their street changed. Retrofitting
existing neighborhoods to become woonerven was prohibitively expensive. The very strict design requirements of woonerven often could not be met. For example, traffic flows in inner city neighborhoods might exceed the low volume required for a woonerf and cause an overflow of traffic onto neighboring streets. Pedestrians complained that there was no designated or protected space for them without raised sidewalks. Finally, the principles of woonerven could not legally be extended to shopping streets or village centers (winkelerven and dorpserven). Thus, in 1984, a Review Panel established by the Dutch Government reviewed the woonerf law and made a number of substantial changes. These new laws were effective July 16, 1988. ‘Me 14 strict design rules were reduced to just six basic principles, close to the original concept of the woonerf, but allowing more flexibility. 1. The main function of the “erf’ shall be for residential purposes. Thus, roads within the “erf’ area may only be geared to traffic terminating or originating from it. The intensity of traffic should not conflict with the character of the “erf.” In practical terms, conditions should be optimal for walking, playing, shopping, etc. Motorists are guests. Within woo5
Figure 7. A shared street in Delft, Netherlands. Source B. Juyoung Jung, Urban Streetscape, Delft University of Technology, 2013, page 63.
Figure 8. A shared street in Delft, Netherlands. Source B. Juyoung Jung, Urban Streetscape, Delft University of Technology, 2013, page 63.
nerven, traffic flows below 100 vehicles per hour should be maintained (300 vehicles per hour for winkelerven). 2. To slow traffic, the nature and condition of the roads and road segment must stress the need to drive slowly. Particular speed reducing features are no longer mandated, so planners can utilize the most effective and appropriate facilities. 3. The impression shall not be created that the road is divided into a carriageway and sidewalk. Therefore, there shall be no continuous height differences in the cross-section of a road within an “erf.” 4. The entrances and exits of “erven” shall be recognizable as such from their construction. They may be located at an intersection with a major road (preferable) or at least 20 meters (60 feet) from such an intersection. 5. The area of a section of the road surface intended for parking one or more vehicles shall be marked at least at the comers. 6. Informational signs may be placed under the international “erf’ traffic sign to denote which type of “erf “ is present. (US Department of Transportation 1994)
streets with many woonerf style treatments such as speed humps, carriageway narrowing and parking management. The woonerven was effective but expensive. The simple traffic diversion method was cheap and largely ineffectual (Hass-Klau: 1990; Hamilton-Baillie 2001). In between came what is now known as the 30 kmph zone (18 mph) where significant speed and accident reductions could be achieved without the high costs of a woonerven.
Since the late 1960’s, this country has applied the concept to more than 7,000 streets and residential areas (Hamilton-Baillie 2001). The two most famous early demonstration projects were established in 1977 in residential areas of Eindhoven and Rijswijk to compare the costs and benefits of a fullblown woonerven with Buchanan-style one-way street systems. In between was a third trial area: 6
The resulting impression created by a home zone is described by Hamilton-Baillie (2001, 6): One leaves the busy main through fare in Rijswijk to find oneself in a set of tranquil streets paved with Dutch bricks, cobbles and pavers. Cars are parked in offset groups shielded by trees, which themselves become the dominant feature of the street. Speed cushions are discrete, and carefully planned into the overall street design, which in turn takes into account a multiplicity of uses. There is beautifully planned seating on corners, play areas separated from the carriageway only by sets of bollards, and a blessed absence of signs and road markings. Street paving patterns have been designed to emphasize the “place” nature of junctions, and deliberately eschew any reference to the “carriageway.” The original home zones implemented in Holland were accompanied by expensive alterations to the existing street layout or integrated into the construction of new neighborhoods. Early home zones provided traffic-calming measures on cul-de-sacs
Figure 9. Cul-de-sac Home Zone in Germany. Source Burden, http://www.pedbikeimages.org
Figure 10. Signage for a home zone/wohnstrasse in Germany. Source: Burden http://www.pedbikeimages.org
shared by pedestrians, cyclists, and motorists, as described by Hamilton-Baillie above. These measures were supplemented by the provision of additional throughways for pedestrians and cyclists. In later home zones, traffic-calming measures, such as speed bumps, raised junctions and bottlenecks were used on a “street layout that was largely kept intact” (Hass-Klau 1990), resulting in big cost reductions. The Delft demonstration project showed that the creation of home zones often relies upon and proves to be most successful when local citizens give input in the redesign of “their” neighborhood street (Hass-Klau 1990; Biddulph 2001).
learned that calming individual streets resulted in traffic diversion and already quiet streets became quieter as traffic moved to already congested streets (Ewing 1999).
The mainly single-street Dutch home zone concept evolved in Germany to fit whole areas, mainly within traffic-calmed residential parts of cities. After word of the success of the homezone prototype in Delft had spread, German planners visited the Netherlands to learn firsthand about the concept.
The Germans began to treat the urban street system according to a new kind of hierarchy: × Arterials and major routes should have a maximum speed of 50 km/hr (33 mph), synchronized traffic lights, bike lanes, marked crosswalks, medians and attractive sidewalk areas for people to linger. × Collector/distributor streets should have a maximum speed of 30 km/hr (18 mph) with design features-such as narrower lanes, bike lanes, wider sidewalks, speed tables-to make this limit self-enforcing. × Residential streets should be woonerf-type streets with carefully managed parking, very slow speeds (walking pace), chicanes, play areas, speed humps, and environmental road closures to deter through traffic (US Department of Transportation 1994).
In the late 1970s, the first study projects were launched in Germany, based on models developed in the Netherlands: streets without a division of street and sidewalk, bottlenecks, road humps, changed street surfaces, and new parking layouts (this was the era when the term “verkehrsberuhigung”, translated as traffic calming, was coined). The success of these pilot studies made home zones and traffic calming acceptable in Germany; it was quickly
During the early 1980s, home zone-type streets (known as “wohnstrasse”) and whole areas were implemented throughout the country. Many cases showed that traffic calming reduced the number of accidents and their severity, the average speed driven, noise and pollution, parking problems and that community interaction increased (Hass-Klau 1990). These programs were accompanied by the Children and Traffic initiative introduced by the go-
vernment in 1980, including a law requiring that drivers be particularly attentive to children. In some cities, the alterations to the street surface and layout for home zones were considered too expensive to be applied to larger areas. Keeping in step with the Dutch, the Germans the developed a less expensive solution, slow speed signs (30 kph; 20 mph) were placed in residential areas that became known as “Tempo 30 Zones” with relatively few alterations to the street design: area-wide traffic calming, or “verkehrsberuhigung.” As with the 30 km/zones (18 mph), they combined the best features of the woonerven with Buchanan’s concept of environmental areas. The road system remained fully connected - unlike in Buchanan’s model, where road closures, diversions and one-way streets kept unwanted traffic away-but traffic speeds throughout the system were to be significantly decreased. Short-cut traffic would be deterred, yet residents could still reach their homes directly. There would be a more uniform distribution of traffic across the area and traffic volumes would be brought into line with area functions and land use policies. The speed reductions would be achieved by applying at critical areas in the network some of the same sort of traffic-calming measures (Tolley, Rodney, Chapter 5, Calming Traffic in Residential Areas, Brefi Press, 1990, Wales). As experience grew, however, it became clear that physical changes to the street were needed to really control vehicle speeds (US Department of Transportation 1994). In 1989, the German federal government elevated local practice into permanent law. Many German cities and towns have now incorporated “Tempo 30 Zones” throughout most or all of their jurisdictions as part of safety programs. For example, about 80 percent of the city of Bonn, with a population of 310,000, is now within 30 km/h zones (HassKlau 1990). Nongovernmental organizations, such as the Verkehrs Club Deutschland (VCD), an alternative transportation advocacy group, and the Deutsche Staedtetag (Union of German Cities) are important lobbyists and promoters of traffic calming (Hass-Klau 1990). The VCD has fostered large-scale public awareness campaigns called “More Tempo 30” or “Vision Zero Fatalities” to reduce speeds (VCD 2004). As a result, speeds of 50 kph (30 mph) are widely regarded as inappropriate for urban residential areas, and speed reducing programs and measures are in effect almost everywhere (VCD 2004). 8
Figure 11. Pilot Home Zone in Leeds, Uk. Source: Methleys Community Action Group.
United Kingdom, shared space The United Kingdom’s urban transportation and planning history took an interesting turn with the introduction of home zones. A 1963 British government document, Traffic in Towns, who’s author, Colin Buchanan, is considered the father if traffic calming in Europe and often credited with launching the modern traffic calming movement. The report was the first official document to recognize that growth of traffic threatened the quality of urban life, but the solutions offered were shortsighted: urban areas were to be reconstructed to accommodate the automobile; neighborhoods were to be protected largely by closing streets and using short oneway segments to prevent through trips; volume control measures were emphasized to the virtual exclusion of speed control measures (Ewing 1999). As early as 1966, a predecessor of the Dutch home zone concept could be found in the United Kingdom, called the “shared space” layout. Like its Dutch counterpart, shared space was based on a cul-de-sac street layout (Hass-Klau 1990).
Many ideas for creating pedestrian-friendly zones and traffic calming existed in the United Kingdom during the 1960s, but they did not begin to attract attention until the late 1980s. Buchanan-inspired traffic calming plans were implemented throughout Britain under the 1969 Housing Act and a 1977 street design manual (Design Bulletin 32, updated in 1992), and the Urban Safety Project, a traffic calming initiative launched in 1982 to reduce accidents. These measures had relatively a modest impact on collision rates compared with the other European countries, and they were implemented not in an harmonic and fainthearted manner (Ewing 1999). A very important role in bringing home zones to the political agenda was played by civic organizations, most prominently the National Children’s Play Council, which has joined with other organizations in actively promoting a British “Safe Routes to School” program (Hamilton-Baillie 2001). The “Children and Road Safety” campaign launched in 1990 and an accompanying regulation permitted for the first time the designation of 20-mph zones. Continued active lobbying by interest groups and growing public awareness of home zones has pushed the topic to the national stage. Changes in law and regulation, and a new edition of the street design manual, have brought Britain into line with the rest of Europe. Regulations were liberalized in 1986 and 1990 to permit the use of vertical measures of traffic calming, and the 1992 edition of Design Bulletin 32 shifted from advocating a tree-like hierarchy of roads to a hierarchical network of traffic-calmed streets. As a result, the UK government has been showing increasing commitment to home zones. The concept now appears in relevant policy documents, including its 10-year transport plan developed in 1999. Home zones have also been the subject of a pilot project initiative and have been accorded a legal basis under Section 286 of Transportation Act 2000 and Section 74 of the Transport Scotland Act. Local traffic authorities in England, Wales, and Scotland now have specific power to designate home zones (Voorhees 2004). Local authorities are using a wide range of approaches to implement home zones. The UK Department for Transport is monitoring the pilot projects, just described, which are focused mainly on alte-
Figure 12. Home Zone in Hull, Uk. Source: Hull City Council.
rations to existing streets. The monitoring process will measure how well the pilot projects are meeting home zone objectives within the existing legislation. Elements that are being measured include traffic volume and speed, street activity, the living environment and changes in attitudes. In addition to the “official” pilot projects, local authorities, developers, and housing associations have set up a growing number of home zones independently across the United Kingdom. Many local authorities now include the scheme in their Local Transport Plans as well (Biddulph 2001; Hamilton-Baillie 2001). Private homebuilders are increasingly aware of the home zone concept and are trying to incorporate home zone features into their developments. Builders recognize that in certain situations, home zones might allow for higher densities and are finding that the concept can be readily marketed as “family friendly.” Furthermore, developers realize that when compared to traditional streets, homebuyers may well be prepared to pay more to live in a home zone. It is important to note that as with the Dutch experience, all successful UK Home Zone pilot projects include citizens in the planning and design process of their streets (Biddulph 2001).
The example of Israel These regulations developed in the European countries were the basis of the guidelines for shared streets in many other countries. In Israel, in the early 1980’s the Ministries of Construction and Housing, and of Transportation formed a Technical Council Committee to review the guidelines of the 1978’s earliest commission and propose criteria for the installation of a shared street; the committee comprised government transportation agency staff, 9
Figure 13. Downtown woonerf design, Kalamazzo, US. Source: Kalamazzo County.
Figure 14. Safe residential Home Zone, Missoula, US. Source: http://www.homeword.org.
traffic engineers from academia and private practice, planners, architetcts, and landscape architects. The revised guidelines were published in 1981 and 1982 were heavily based on the already european calculated experiments and regulations, and included these conditions for creating a shared street: × the area must be zoned as residential; × analysis of existing traffic conditions and traffic impact must be carried out; × design must follow planning guidelines as well as redient’s input. A research team was then commissioned to devise revisions of build streets. This research led to the 1987 legislation adopting the shared street concept, in a specific traffic ordinance (Ben-Joseph 1995).
The woonerf concept became so common in Israel that thoso who controlled the planning and design process of streets, the road engineers, felt professionally threatened. To calm the waters, the Ministry of Construction and Housing decided to charge the landscape architect for the physical design and the road engineer for subgrading and drainage (Ben-Joseph 1995).
Also in Israel, residents, developers, and manufacturers of concrete pavers were quicker off the mark than was the government in adopting the woonerf concept. In 1981, and initiative by the residents to eliminate through traffic on a residential street led to the first shared street design in a suburb, and encouraged by the positive results the local municipality commissioned three more streets. The economic actors such as concrete paver manufacturres, realizing the economic potential, then lowered their prices to be competitive with bituminoes paving and began an advertising campaign for shared streets. Developers adopted the concept and often used it as a sales pitch for their communities as safer, green, and more aesthetically pleasing. 10
United States of America Most of the woonerven implemented in the United States are shared streets in commercial areas. Good examples are found in Asheville, NC (Wall Street) (Alan M. Voorhees Transportation Center. “Home Zone Concepts and New Jersey,” 19), San Francisco, CA (Linden Street) (Langdon, “Shared-Space’ Streets cross the Atlantic”) and Cambridge, MA (Palmer and Winthrop Street). However, woonerf implementation in residential areas is rare. Two known cases are The Cottages and Bridgewalk in Boulder. Both projects were built based on the woonerf concept; however, both had some difficulties applying the concept. For example, in the case of Bridgewalk, houses already had backyards, porches, and other areas for people to congregate, so the shared street was used more by cars than people (Voorhees 2004). Much of the reasons why some of the home zone s may have not been to much successful in US are usually practical. European cities tend to be more compact than United States cities and cannot cope with the volume of traffic experienced in the United
States. Car ownership is still higher in the United States than in most European countries. European cities tend to have better public transport services already in place and local governments have much greater control over land use planning and development than their counterparts in the United States. Another example is on Appleton Street in Boston, where the street and house typology are very similar to a European street. It was converted into a woonerf in the 1980s. Appleton Street’s design includes a raised entrance, traffic calming measures, and angled and parallel on-street parking. While it does have different pavement materials, there is a continuous curb. The most useful example is the Borderline Neighborhood Shared Streets Project in Santa Monica developed by Nelson\Nygaard Consulting Associates in collaboration with other consultants. The project retrofitted four connected streets into a community front yard that promotes walkability, adds sustainable landscaping, and provides community gathering space. The project raised the roadbed to eliminate vertical curbs and used decorative pavers to delineate walking, driving, and socializing spaces. It also incorporates sustainable features such as urban runoff retention elements, permeable concrete and pavers and solar lighting. The project took nearly six years to be completed and cost $2.1 million.
Design Elements of a Home Zone Most of the examples of woonerven are in the Netherlands, Germany and the United Kingdom, but the concept has spread through Europe as well as Japan, Australia and Israel. While each country has implemented the woonerf scheme, there is no cookie-cutter design for a woonerf. This means that each country - and place - has transferred the core concepts of a woonerf and created their own safe areas according to their needs and local culture. Each woonerf implementation requires a distinct approach to street design, so the woonerf core concepts are clear and adaptable; and they consist of the following guidelines: × Have a clear and distinct entrance: A woonerf should be marked by some kind of entrance so people going into the street will know that this area is not a typical neighborhood. This can be achieved by incorporating gateway features such as
Figure 15. Hand made paving bricks in Methleys, Uk. Source: IHIE, Home Zone Design Guidelines, 2002, page 18.
All home zones… share(d)… common characteristics. Typically these include lack of separate raised pavement, a variety of surface treatments…, the use of trees, planting and street furniture to define and screen parking, the use of bollards and street lighting to define space, and the use of simple “gateways” at the entry points. But.… the striking quality of Woonerf streets is their individuality. There is no common template, every street is treated differently. This of course stems from the simple fact that every successful home zone is designed and adapted according to local preferences and circumstances, with residents and users involved at the outset. Hamilton-Baille (2001, 17) trees and planters, curbs extensions to make the carriageway narrow, and a ramp up to the shared surface. Any of these approaches should be also accompanied by a sign indicating the woonerf status. Exits from the woonerf should therefore also include a sign indicating the end of the status. × Eliminate the continuous curb: Pedestrian and auto space should be on the same level. Shared surfacing encourages drivers to travel more slowly and carefully since there is no clear definition of the travel lane. Using different colors or textures in pavement material is also important for guiding the users of the street within the carriageway (e.g., pedestrian vs. auto lanes). By eliminating the continuous curb, residents - especially children - can move freely across the entire space. × Use traffic calming measures: The design of the street should add slight curves to break up the sightlines of a driver and also introduce physical and visual features that will encourage people to drive slowly and with greater caution. These measures include chicanes, speed bumps and cushions, narrow travel lanes, small corner radii, different pavement treatments, as well as other elements 11
Figure 16. Home Zone design in Northmoor, Uk. Source: IHIE, Home Zone Design Guidelines, 2002, page 74.
Figure 17. Home Zone design in Morice Town, Uk. Source: IHIE, Home Zone Design Guidelines, 2002, page 58.
such as street trees, bollards and furniture. According to Biddulph (2001), these measures should be located less than 160 feet apart so there is no length that would allow drivers to think they have priority over pedestrians and bicyclists, but at the same time they should be designed so they do not represent a hazard if they are passed at an inappropriate speed. Furthermore, these traffic calming measures cannot be an obstacle for emergency responders. It is recommended that planners and architects engage emergency responders in a collaborative approach to designing traffic-calming elements. Ă— Provide on-street parking: Parking should be provided intermittently rather than continuously so the car is not the predominant element in the street. Areas in which parking is permitted should be indicated by physical elements (e.g., bollards) and/or different pavement material. Parking arrangements should also be used as a mechanism to calm traffic. There are a few common strategies to arrange parking as well as code allowance.
Ă— Incorporate outdoor furnishings and landscaping: Street trees and planters make the street look more attractive as well as calm traffic. Tree planting should be carefully coordinated with existing or planned underground utilities to avoid conflict. Seating also should be included to encourage people to use and stay in the street for other activities. Seating areas should be protected from cars, using bollards or other physical barriers.
According to Biddulph (2001), a woonerf works better in areas in where there is resident support as well as existing street activity such as children playing on the streets. It also works better if the streetâ€™s current traffic is considered dangerous by the residents, discouraging people from going out. Also, a woonerf would be more successful if there is little or no open spaces available close by. As a result, woonerf implementation should not be applied in isolation - instead, it should be part of a wider strategy such as an area-wide traffic calming initiative, a related safety initiative (e.g., Safer
Route to School), or an expanded pedestrian and cyclist network, among other possibilities. Research also suggests that streets need to be used by fewer than 100 vehicles per hour at peak times. In addition, the area treated should be less than 1,968 feet long (600 meters). However, Appleyard and Cox (2006) recommend a length of 300 to 500 feet. Even though there is no clear justification for determining the street limit, research suggests that shorter distances might reduce driver frustration at having to drive slowly through the woonerf.
Figure 18. Morice Town masterplan, Uk. Source: IHIE, Home Zone Design Guidelines, 2002, page 59.
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