The A1321 is a link road through Basildon New Town in Essex. It is D2 in its entirety.
The route starts in the town centre at a roundabout on the A176. From here it heads east along Broadmayne, a name it retains for its entire length. Initially there are frequent sets of traffic lights as the road skirts the northern edge of the town centre, and soon there are houses on both sides of the road, although since this is a New Town none are actually accessible from the A1321 itself. The traffic lights are left behind as well.
As we continue east we go under a pedestrian footbridge adjacent to a LILO junction; the same happens again shortly afterwards although this time there is only eastbound access. A roundabout is then reached, where we meet the B1419. After another footbridge and eastbound LILO we pass a school to reach a final roundabout, where we end on the A132.