Disc parking which can make a one-hour parking zone as short as thirty minutes, possibly resulting in an unjustified parking ticket. On March 31, 1979 the conference of ministers of transportation in the European Union decided that a European standard should only use designs with a single clock face. The standardized clock disc was introduced as federal law in Germany in November 1981, and similar designs were adopted in other European countries. From 1998 the old parking disc designs began to be abolished. France set the last date to 2007, while in Switzerland (not an EU member) the EU parking disc design
The High Cost of Free Parking by which governments can collect revenue from parking and how it can design parking meters and systems to respond to price signals. Shoup concludes the book by recommending three main reforms which can be made to improve parking policy. He suggests charging fair market prices for curb parking, returning parking revenue to neighborhoods for community investment, and removing the requirements for off-street parking for new development. "The High Cost of Free Parking" received generally positive reception. Reviewers generally found the book very comprehensive and practical for planners but also overly long and lacking in political solutions to parking's planning problems.