M10 becomes A414

The M10 from Park Street Roundabout to M1 Junction 8 has now been de-trunked and become part of the A414.
This means that it is legal to cycle on it. Not a particularly pleasurable experience but it does offer the most direct route between Park Street & Hemel Hempstead.
Hard shoulders have been retained, so you are able to ride well separated from the running lanes for the majority of the route.
At the north end, north bound, there is no hard shoulder, only an edge-of-carriageway line a metre or so from the edge of the black top, which affords some degree of separation. Traffic lights control the merge with traffic which has left the south bound lane of the M1. Beyond this, towards Hemel, there appears to be no facility you can use for segregated cycling.
At the north end, south bound, again there is no hard shoulder. The split point of M1 north bound traffic from A414 traffic offers serious conflict possibilities. The narrow 'lane' inside the edge-of-carriageway is rather more usable because of a smoothly contoured water run-off gutter gives a greater effective width.
At the south end, the hard shoulders do not start/end at the roundabout, but fall short by some 20 metres.
I believe that there were once cycle lane markings at the north end, but these have now been removed.
I have not cycled the road yet, only observed it whilst driving a car, so I will have missed some details. These will be added when available, possibly with a few photos.
I believe that it is much less dangerous to use than the A414 between Hatfield & Hertford (which I have ridden at a fairly busy time) where there is no hard shoulder or footway to use to avoid traffic & no lighting. The old M10 retains its full motorway standard lighting, all the way to Hemel.
Clearly there are points which demand great care, judgement & experience. I suggest you make your own recce by car before riding the route.
Please add informed comments to this post.