Judging by the TAR Can 1 & TAR Can 2 filming start dates, I can estimate/speculate the following:
= The Race usually starts filming on a Friday, because
- TAR Can 1 started filming on
Friday, May 3rd, 2013.
- TAR Can 2 started filming on
Saturday, April 26th, 2014.
= The Race did not start last week (or at least we don't know about it), so it seems that the race would most likely start on
Friday, May 1st, 2015 or Saturday May 2nd, 2015..
NOTE that this is an estimate using judgment from previous seasons and the actual start date is still unknown. My suggestion is to continue searching social media in case we get an actual sighting