Ive been thinking on this some more and I think I have got somewhere. If I
use a daily total then the hours 1x can be more than 8 because travel is
included but only ever paid at single time. What I could do is add the travel
time into the total column regardless, I could then (somewhere else on the
sheet) total the site time and have a formula that says if the site time is
less than 8 add to the total column, if it is more than 8 add the 8 to the
total column and put the left over in the 1.5x column.

I just dont know how to tell a formula to split numbers like that i.e. if
over 8 put the remainder somewhere and the 8 somewhere else.