Amsterdam experiment in mixing pedestrians, trams and bicycles, The

Institute of Transportation Engineers. ITE Journal, Aug 1999 by Zacharias, John

The regularity of our data is important to our conclusions, especially in light of the variety of movement patterns. Several studies have related the volume of pedestrian movement and limited observations (see Ref. 11 for instance). Haynesl2 provided a way to estimate the sampling error in pedestrian counts, using the pedestrian environment in Norwich. At the flow rate and for the sampling times in our street, we could expect about 10 percent error (at p

At these suboptimal conditions, traffic streams already show a statistical tendency to right-handed travel but with the opposing movement completely mixed. There is no observable reduction in speed in this arrangement although there is a need to be alert to possible collision with other pedestrians. For the cyclist in particular, the challenge is substantially greater since people in the street are moving toward and away from their own moving bicycle and in a constantly changing distribution across the width of the street. While cyclists tend to seek the underused central portion of the street, they share a relatively narrow strip. The space between the rails is just wide enough for two bicycles to squeeze by with a clearance of a couple of centimeters, otherwise requiring a fairly sharp movement to cross the rails at an obtuse angle. Cyclists tend to keep to the right of each other within the available channel for them (Figure 4).

Moreover the individual paths are clustered together in a relatively small part of the available channel. Figure 5 illustrates traffic density on the same section of the Leidsestraat as illustrated in Figure 1.

Shoppers make up only 5 percent of the traffic in any one section of the street. Since the street is long, a higher proportion of the pedestrians are also shoppers at some part of the street, but they do not behave as shoppers for the most part. Shoppers tend to weave across the streams of traffic, deferring to the through movement and only occasionally coming into conflict with others. Other shoppers cling to the relatively untraveled portion of the street next to the building facade. Much more cross movement is encountered at the block ends where transversal streets carrying car traffic cross the Leidsestraat. At this point, cyclists and drivers attempt to cross the Leidsestraat traffic streams without explicit rules or traffic lights to guide them. Cross movement defers to through movement, although this often amounts to edging into the stream until pedestrians yield the right of way.

Finally, we considered the question of whether pedestrians and cyclists tend to distribute themselves variably across the street surface at various densities. Our measurements from each individual to the three nearest neighbors were thought to capture all spacing maneuvers individuals were likely to engage in. These measurements included those individuals walking together who could not be expected to disperse at lower overall pedestrian density. We can nevertheless observe a tendency toward dispersion over the whole sample, as shown in Figure 6. This means that an increase in density does not produce a linear increase in pedestrian presence over the road surface.