the a12 ran through lowestoft for about on urban limited roads. however, as of june 2006, the a12 now follows the course of the new single carriageway southern relief road that joins the original a12 at lowestoft bascule bridge. a further impediment is the harbour bridge, which has three lanes, the centre lane operating as a one-way addition to whichever direction of flow is deemed greater. the presence of these bridge choke points can cause serious disruption to north-south trunk traffic, especially when local traffic is added during rush hours. an adequate bypass for lowestoft would need to be well to the west, even to the west of oulton broad (the body of water), and its route would have to consider the great areas of marshland in that area. for that reason an often discussed compromise is a third bridge, crossing lake lothing, linking the sections of urban spine-road that run approximately along the western edge of lowestoft.