|Location Map ( geo)|
|To:||London Colney (TL163049)|
|Distance:||7.2 miles (11.6 km)|
|Meets:||A5183, A5135, B556, A414|
|Route outline (key)|
The B5378 is a secondary spine route in south Hertfordshire. It was originally unclassified but gained its number around 1930.
The road starts on the A5183 (former A5) on the northern edge of Elstree village and heads east along Allum Lane, which has a weight restriction from the outset. The road soon becomes residential - this is that part of Elstree which is a suburb of Borehamwood. After crossing a mini-roundabout we go over the Midland Main Line above Elstree & Borehamwood station. There's a mini-roundabout on the far side after which we enter Borehamwood town centre.
We continue east along Shenley Road, one of the main shopping streets, which is intermittently D1. There are a couple more mini-roundabouts then a full-size one, after which the road becomes D2. The A5135 (which starts here) bears off at the next roundabout along Elstree Way, whilst we continue north, now S2 and residential once more. We climb Cowley Hill out of town and then would come in sight of open fields were the hedges not too high to see over.
The road isn't rural for long as we soon reach Shenley, where we bear left at a mini-roundabout to head northwest through the village. It takes a while to return to open country (this time the fields are visible from the road), after which a more-or-less straight road takes us to a roundabout on the B556.
Originally the B5378 ended here; the section to the north was only classified following construction of the A414 in the 1930s for our road to connect to. We therefore continue on and immediately go over the M25 before reaching London Colney. We skirt the western side of town, with nothing on the left and houses on the right set back behind a service road. A roundabout provides access to Napsbury Park (formerly the Middlesex County Asylum, now a residential development using some of the original buildings) then there's another field or so before we reach the A414. A road to the right meets the westbound carriageway at a LILO, after which the B5378 follows that road for a short distance before crossing it. The eastbound sliproads are met on the far side of the bridge and the B5378 ends here. The unclassified road ahead continues into the southern suburbs of St Albans.