Groningen's Traffic Circulation Plan (1977) — Four Sectors Closed to Through Car Traffic in One Night

In 1977 the Municipality of Groningen introduced the Traffic Circulation Plan (VCP), dividing the inner city into four sectors that cars could not cross; motorists had to use the ring road, while cyclists, pedestrians and buses kept direct access. It was introduced over one weekend and drew strong protest from shopkeepers and business organisations, with limited public participation.
Municipal investigations summarised in a 2007 University of Groningen research report (Tsubohara): hourly private-car traffic in the inner city fell 47% on average; the car share of trips to the inner city fell only slightly (36% to 34%) because the plan removed through traffic; bus passenger numbers to the inner city rose 12% on weekdays and 17% on Saturdays; perceived safety and noise/odour assessments improved; and visits to the commercial core rose 22% (357,500 to 436,300 a week). Total weekly inner-city visitors fell 9% in one survey, and a business survey recorded a 2.2% annual decline in visitors, with 25% of responding businesses reporting lower sales. By 1981, firms reporting lower sales had fallen from 25% to 14%.
The plan was modified in 1982 after business demands for deregulation, with the changes kept to a minimum. Later Groningen cycling-strategy documents credit the plan as the base of a cycling share of about 60% of trips today, a figure from secondary sources and not isolated from other factors.
The case is valuable because it records both the large traffic gains and the real, if smaller than feared, retail costs and the participation shortcomings.

Read the full analysis: https://pure.rug.nl/ws/files/14433101/317.pdf