|Length:||25.9 miles (41.7 km)|
|Meets:||A1304, B1063, B1103, A14, B1102, A1123, A10, A1421, B1381, B1098, A141|
|Route outline (key)|
The A142 is one of those largely flat fenland roads that has been improved with a number of smaller bypasses and realignments over the years.
It starts at a mini-roundabout on the A1304 (former A11) on the edge of Newmarket town centre. It heads north out of town along Fordham Road, crossing the A14 at J37 where it becomes primary. After crossing the Ipswich to Ely railway line it meets a roundabout marking the beginning of the first of several bypasses on the road, this one being of Fordham.
The Fordham bypass runs into the Soham bypass at another roundabout, after which the A142 rejoins its current route at a third. With the road now almost completely flat, a large building becomes visible in the far distance; this is Ely Cathedral, a landmark for miles around. It gets closer and closer as we approach Ely itself and eventually cross the River Great Ouse to reach the railway line on the edge of the city.
The railway crossing is an unusual one, with a very low bridge underbridge (2.7 m) beside the level crossing adjacent to the station. The bridge is the through route with traffic using the level crossing having to TOTSO and then give way. The crossing is currently in the process of being bypassed by a new southern bpass.
Meanwhile, until the bypass opens, having crossed the railway, a mini-roundabout is reached. The original A142 continued ahead to the cathedral where it met the A10, with which it multiplexed out of town to the west. Now the A142 has been diverted via Angel Drove to the western bypass but still needs to multiplex along the A10.
The A142 regains its number at a roundabout and heads west along Witchford Road, although Witchford itself is now bypassed. After passing Sutton it crosses two fen drains before reaching Chatteris. Originally the road ran into town where it ended on the A141 but both roads now bypass Chatteris, the A142 running round the west and north sides of the town to end at a roundabout where the A141 returns to its old route north of the town centre.