Mack Donoghue’s recent letter, “So just stop driving?” offers an entertaining parade of luxury SUVs, ski-laden families and contractors towing trailers. It is also a straw-man argument. Nobody planning the Bobsled Express believes every Deer Valley or Vail Resorts visitor will surrender the keys to a rented Suburban. Nobody expects a plumber to bring tools and materials onto a bus. The project does not require everyone to stop driving. It was ne…