On April 1, the Supreme Court agreed to allow U.S. Solicitor General Donald Verrilli to argue against a concession agreement involving the clean truck program at the Port of Los Angeles. The case challenges a decision by the U.S. Court of Appeals for the Ninth Circuit which placed a federal market participant exception on a city port. The resulting concession plan includes off-street parking to prevent idling and the posting of telephone numbers to report diesel emissions. The court will hear oral arguments on April 16.