I walked the TT course some years ago in three parts. First day Douglas-Kirk Michael, second day Kirk Michael-Ramsey and the third day Ramsey-Douglas. That was in Easter time in nice weather. As it was a non racing period it didn't feel dangerous. Mostly calm and nice traffic. Of course I had a orange west on to make me more visible. At the first two days there is mostly a pavement on one side of the road. Over the mountain the third day you have to run on the road, but there is a pavement again when you come to Hillberry, closer to Douglas. At race time I wouldn't do it. Bikers and cars can crash anywhere and hit you when the control over the vehicle is lost. Even if you're on a pavement they'll hit you! DANGEROUS!