It takes a train travelling at 125mph 1.25 miles to stop after applying full brakes, according to Railtrack which has commissioned one of this year's Fringe plays. A "hard-hitting drama'' for 10 to 12-year-olds, set beside an urban railway line, I Dare You tells how peer pressure and acts of vandalism can result in tragedy. Performed by the Figment Theatre Company, the play runs at the Pleasance Theatre, August 18-30. Free for local schools; Pounds 4 per ticket for others. Given sufficient interest, Railtrack may arrange a tour of Scottish schools in 1998-99.