I have found an interesting article about the average walking speed of people in 30 capital cities. This is a great study material. I have seen in Paris and London small zone maps that indicate the maximum distance a pedestrian can walk from the bus station within 4 or 5 minutes.
The map is positioned in the center of the blue circle. The two circles delimit the 5, respective 10 minutes walking distance. This distances are specific to the local average walking speed and should vary from city to city.
By extrapolating data presented in the article, I was able to make some projections for several cities in Europe.There will be a total of 10 to 12 articles. Note that the city with the fastest people is not in Europe.
Some rules have been followed: no roads to be crossed, no traffic lights to slow down the people. The realistic scenario would imply complex curves, closer to the isoclines.
The capital of Denmark is a place where people walk very fast. I am a bit surprised, for Danish are not known as stressed people. The explanation may be related to the high percentage of people having a practice of sports.
The diameter of each circle is in fact the walking distance from its center in the allotted number of minutes. For example, in 4 minutes, one can walk a little more than 400 meters.