The Federal Administrative Court in Leipzig is hearing an appeal by two German states against lower court rulings that suggested driving bans for particularly dirty diesel cars would be effective and should be seriously considered as a means of protecting public health.
The court has said a verdict could be issued as early as later today. If judges reject the appeal, dozens of cities would have a few months to enact measures to remove heavily polluting diesel vehicles from the roads -- an administrative nightmare for local authorities and a heavy blow to drivers who bought cars they were promised met emissions standards.
German car manufacturer Volkswagen was found three years ago to have used in-car software to cheat on US diesel emissions tests. The discovery resulted in large fines and costly buybacks for VW in the United States, but the German government has refrained from punishing VW, a major employer that's partly owned by the state of Lower Saxony.
Apart from hitting Volkswagen and other German carmakers, officials warn that a ban could paralyse bus companies, garbage collection services and tradespeople who rely heavily on diesel vehicles.
In a bid to avoid punitive action by the EU, German officials recently proposed a series of steps to reduce harmful emissions, including making public transport free on days when air pollution is particularly bad, and requiring taxis and car-sharing companies to use electric vehicles.
Automakers are particularly worried about another government proposal: forcing them to physically upgrade millions of vehicles that don't conform to emissions limits.