The Comber Bypass was built in two phases thirty years apart and connects the Belfast Road to the north west to the Newtownards Road to the north east, and passes round the south side of the town on the line of the former railway line. Phase 1 (mid 1970s) connected the Belfast Road to the Killinchy Road while phase 2 (2003) connected the Killinchy Road to the Newtownards Road. Because of the hilly nature of Comber, the bypass passes over Mill Street and under the A21 Ballygowan Road. A short link road connects Mill Street to a T-junction the Belfast Road. This sketch map illustrates the current arrangement:

The problem with this is that there is no convenient connection between the A21 Ballygowan Road and the Bypass. Quite a lot of trafic approaches from this direction and must either drive along Railway Street (a residential area) to the T-junction to the north, or else continue to The Square in the centre of town via The Brae or Mill Street (defeating the purpose of a bypass). To make matters worse both The Brae and Mill Street are narrow streets and in places are not wide enough for two vehicles to easily pass each other.

The plan, sometimes referred to as "Phase 3" of the Comber Bypass, would connect the Comber Bypass directly to the Ballygowan Road, probably by building a short 90° link road between the two beside the bridge. However, Roads Service are not in any hurry to provide this link and currently there are no plans to proceed in the near future. At the time of writing (March 2008) the Ards and Down Area Plan is still being worked on, and may or may not recommend proceeding.