Chapter 10 - New Ideas: Beyond Traffic Calming

Introduction

Since its introduction, traffic calming has enjoyed a moderate level of success in the United States. At this time, simple traffic calming devices like speed humps and bulb-outs are relatively easy to find in residential neighborhoods and small downtowns. But the typical approach in this country is to install a device to slow down traffic, and then install more along the street until the desired affect is reached. There are, however, experiments and systems in place around the world that take a different approach. This chapter will focus on new ideas being developed, tested and approved in some European countries.

Pedestrian Priority Zones

These zones can be designated in single streets, open squares, or over an entire system of roads. The identifying characteristic of these zones is that while pedestrians and motor vehicles can both occupy the area, pedestrians always have the right of way. Vehicles must stop and let any pedestrians move uninterrupted. In these zones, the pedestrian is king. For these actions to be possible, speeds must be kept very low. In some areas with very high pedestrian volumes it’s hard to drive fast anyway. In other areas with lower foot traffic, creative traffic calming is used to keep speeds down. These zones are becoming increasingly popular in Germany and Switzerland. These zones have their roots in the Dutch Woonerf, or Living Street, in which vehicle traffic was slowed down dramatically to afford an extra measure of safety for children playing near the road.

The most recent evolution of the pedestrian priority zone is the Begegnungzone, which translated from German means “coexistence zone”. As expected, in these zones the pedestrian gets preferential treatment. The defining aspects of the Begenungzone are¹:

• Pedestrians traffic always gets precedence, even over public transportation.
• The pedestrians may not, however, obstruct traffic unnecessarily (no loitering in the street).
• The posted speed limit is 20 km/h.
• Signs mark the entrance to these zones and display the speed limit.
• Parking is only allowed in designated areas.

These zones are limited to local and collector roads in residential and commercial areas. Switzerland officially adopted the coexistence zone in January 2002 and it is now standardized and reglemented. The Swiss city of Berne has multiple Begegnungzonen and has maps available that point out all of them. The zones in this city can encompass several streets in a network. Figure 10.1¹ shows a map of one of these zones and Figure 10.2¹ shows a picture from that zone. The Swiss city of Biel has a good example of a coexistence zone in the style of a public square. Shops lie around the central area, and vehicles and trolley buses can pass through the square, but the pedestrian still gets priority. Figure 10.3¹ shows a picture of this location. The benefit of these zones is that they force traffic calming by design. If it is understood that pedestrians can cross the road whenever they choose, drivers must maintain lower speeds to have the reaction time necessary. This uncertainty will also force drivers to become more aware of their surroundings and keep a constant eye out for pedestrians. The Swiss website http://www.begegnungszonen.ch/home/zone_liste.aspx contains a list of more than 100 examples.

Figure 10.1 – A map of one Begegnungzone in Bern, Switzerland

Figure 10.2 – A picture of a Begegnungzone in Bern, Switzerland

Figure 10.3 – Begegnungzone in Biel, Switzerland

Tempo 30 Zonen

Tempo 30 Zonen is the German term for the 30 km/h speed zones that have appeared All over Europe. They originated in Germany in the early 1980’s and have been adopted extensively in Switzerland. The city of Zurich has actually been completely transformed into a 30 km/h zone, excluding arterials and highways. The distinctive feature of these zones is that they are set up over a designated area as opposed to setting the speed on a street-by-street basis. These zones are becoming more common in residential neighborhoods and along collector streets. While it is not uncommon to see residential neighborhoods in the United States with low posted speed limits, there has not yet been a movement to actually district these areas out and specify them as special zones. The innovation of this program is really the scale to which it is implemented. The drive behind creating these low-speed areas is the proven and significant reduction in accident frequency.

There are certain requirements for these 30 km/h zones. First, a technical report must be developed to prove the usefulness and applicability to the area in question. If approved, the area in question must be no more than 1 square km in size without any major highways. Signs must be posted at all entrances and exits to inform drivers that they are entering the zone. Figure 10.4 shows the official entrance and exit signs. It has also been shown that while the signage helps, extra traffic calming structures will need to be installed to insure the necessary reduction in speed.

Figure 10.4 – The entrance and exit signs for a Tempo 30 Zone.

A study done in the hopes of quantifying the actual benefits of these zones has yielded some good results². All of the zones analyzed had a previous speed limit of 50 km/h and were picked from various types of environments. The main findings were as follows:

• Total accident reduction for all zones studied was about 15%, while severity was decreased by 27%. Table 10.1 below summarizes the results in accident analysis.
• A cost benefit analysis showed that the project would pay for itself within three years and could thus be considered completely sustainable. In this case, benefit would mean benefit to society, measured by reduction in cost associated with accidents (car repairs, hospital bills, etc.).
• The zones were found to provide a positive impact on safety while at the same time being economically viable. The final recommendation of the study was to install more of these zones as soon as possible.

Naked Streets

Naked Street is a popular term for a road that has no traffic markings of any kind. There are no delineations for traffic lanes, no traffic signals, no regulatory signs or markings. There are not even separate walkways or sidewalks for pedestrians. It is simply a strip of pavement to be used by everybody.

The philosophy behind these streets is called “Shared Space.” Shared Space is the name of a European project which is currently reexamining the way public space is used within the city. They were running seven experiments in Netherlands, Germany, Denmark, Belgium and UK to examine the effects of person/vehicle space integration at this high level. This project is relatively new and is scheduled to end in 2008.

The driving mentality of the unmarked street idea is that if a person is not given explicit instructions on what to do, they will have to rely on common sense and a heightened level of awareness. Current guidelines for marking and controlling roads are designed to make driving easier. At every point along a journey a person receives instructions on what to do; traffic signals tell them when they can turn left, signs tell them how fast they can safely travel, and illuminated green silhouettes tell them when they can cross the street. All of these steps are meant to provide order and thus reduce conflict on the road. The question is whether or not this is actually increasing safety. If people are told when to stop and go they may tend to pay less attention to their surroundings and potentially miss a hazard. The Shared Space project makes the point in one of its publications: “What feels safe is not necessarily safe. The biggest mistake you can make is to give people the illusion of safety.” If there is no illusion of safety created by road markings people will have to take it upon themselves to make the situation safe. Figure 10.5³ shows an example of one of these naked streets.

Figure 10.5 –The complex de Brink road junction in Oosterworlde, Netherlands.

Conclusion

The unifying factor that makes both of these systems different from current American methods of traffic calming is the scale on which they are applied. One could say that the real innovation coming out of these European countries is the idea of calming traffic across an entire region. Entire downtown road networks are being subjected to uniform measures. If a person were to look into history and decide that the Dutch Woonerf was the original model upon which all of this is based, then the natural progression seems to be traffic calming on an increasing scale. The next step could be traffic calming of entire cities, where the pedestrian priority zone is common and the arterial and highway are the only roads where a motor vehicle still gets the right of way. Given the proven increase in safety by these zones, it may be a good goal for the future. European countries also tend to be much more willing to perform experiments in this field, and to allow them to run several years before making any final decisions. This positive attitude gives innovation a much better chance of occurring.

References

1. Fussverkehr Schweiz, Swiss Pedestrian Association. Begegnungzonen, www.begegnungzonen.ch/home/index.aspx
2. Lindenmann, Hans P. The Effects on Road Safety of 30 Kilometer-Per-Hour Zone Signposting in Residential Districts. ITE Journal, June 2005, pp. 50
3. Shared Space. Shared Space: Room for Everyone, A New Vision for Public Spaces, June 2005

This chapter originally written by Jeffrey Siggers, 2005, as part of a senior project.