By Bus: The local bus line, PAT, runs a special bus between CMU and the airport, leaving every 45 minutes. It's called the 28X. At CMU the bus stops in each direction on Forbes Avenue, near the intersection with Morewood; from there, walk to LTI (white building labelled "LTI" on
this map; north is down). CMU and the airport are the ends of the line, so it is hard to make a mistake. The 28X's schedule is available on-line
here.
The simplest walking route is to backtrack down Forbes past Hamburg Hall, and then follow the driveway (gray on
the map) to the nearest entrance of Newell Simon Hall.