Here is what I now have.

In the 1x column I have =(D3-C3)+(IF((F3-E3)<=8,(F2-E3),8))

This has travel finish in Column D, travel start in column C, Site finish in
column F and site start in column E.

In the 1.5x column I have =IF(F3-E38,(F3-E3)-8,"")

Now I just need to extend it to incorporate multiple rows for each day, are
there any glaring weaknesses?