From Caterham Cars:
To improve the current traffic situation in delightful Dartford, Kennet Road is temporarily becoming one-way. We are told that this will mean no more traffic lights at the end of the road, whilst they build the roundabout that will ultimately be there.
The one-way system means you can no longer turn into Kennet Road, but instead go just a short distance further along Thames Road (towards London) to the roundabout and take the last exit into 'Optima Park' industrial estate. The route into Kennet Road is then clearly signposted with diversion signs.
Once into Kennet Road (which will become immediately obvious compared to the lush tarmac of the new Optima estate), you are abandoned by the signage. So take the first (and only) left hand turning, which is perhaps 50m (55yds in old money) from the start of the road. Follow the road around to the right and bingo, the Caterham factory is just along the road on the right hand side.