Agree with cookeaa, the national cycle routes are great, I commute from outside Reading (Aldermaston) to Newbury and its a great ride and very welcome indeed. Its that or the A4 which is just too mental in the rush hour.
At the moment a section is closed for lock repairs so I ride through Thatcham to Newbury. The dedicated cycle lanes are a nightmare, full of dog mess, glass, kids and you have to stop at pretty much every junction.
So for that section I brave the A4 and have really started to enjoy moving through the traffic, but drivers get annoyed at me for not using the cycle lanes and shout and beep….(as I overtake them)