Water main entry change from1/2" to bigger to change pressure
There is a difference between pressure and flow rate. 

Pressure is the power with which the water presses against valves; this won't change with the diameter of the pipes.

Flow rate is how much water comes out at a time, this will get better depending on the smallest diameter along the run and which other taps are open (in other words the smallest choke point). So if the entry is large up until the first branch at least then it will increase flow rate when both sides are being used but not for an individual tap.