Where? Boho/College area
I think I have the Thornaby to Boro bit down, I use the 8 bridges route that you mention, drop onto the bike path at the port then a quick dash on road from there gets me to the office. The biggest problem with that route is the number of other people on bikes, especially those with no spatial awareness!
Direct is not the problem, idiot smoggy drivers are, especially for my colleague who gave up cycling after being knocked off by a driver.