Carlos, you've done a dash down the A120 before right? Is it likely to be safe/quiet at about 3:30am between Marks Tey and Braintree?
Yeah, it`s OK tippers, it is quite narrow in places, especially near Braintree which means traffic squeezes you if there is something coming the other way, but at 03:30 the traffic is very light, trucks usually pull out and pass completely on the other side of the road. You can detour through Coggeshall which is more direct and about 25% of the distance. New surface is fast too. Might not be quite so good riding back on a Sunday evening though.
It`s suprisingly awkward cycling North, South or West from Colchester and you can`t get far East without a boat!