Three-way traffic lights are causing long queues in the centre of Borehamwood this morning.
Read more: Disruption to last the rest of the week because of roadworks
Lights were put up near the Asda petrol station roundabout in Allum Lane yesterday.
Traffic is built up along Shenley Road from past Tesco towards Elstree Way.
It is also slow on Theobald Street approaching the station, and on Furzehill Road towards the town centre.
Affinity Water is carrying out "essential maintenance" which is scheduled to finish today, according to Hertfordshire County Council's roadworks website.
The roadworks affected drivers heading home last night as well.
There are also delays on the A411 towards the traffic lights in Elstree from the junction with Furzehill Road and the A1 is slow southbound towards Stirling Corner.
You can see all roadworks here
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