I've cycled that route a few times (Woking, Jacobs Well, Guildford) and never used the shared path...I'm normally going so fast (
) that I don't see the shared lanes or I'm on the other side of the road or I just don't want to slow down/stop in order to get onto it.
I quite often see pedestrians and the odd person on a bike using it.
Which route? I normally go Woking - Jacobs Well before rejoining the main A320 Guildford - Woking road at the junction of the A320 with Jacobs Well Road. The route between Woking and Jacobs Well Road/A320 is only about 100 yards longer than following the A320 the whole way but much nicer to cycle, however from Jacobs Well to Guildford I normally just head on the main road (it's basically stop-start the whole way due to the traffic lights, and 30mph limit, so feels less hostile than a 40mph road).
The route Jacobs Well - Clay Lane - then either via the nature reserve to Guildford Spectrum or via Burpham on the main road is slower and further unless your destination is out of Guildford town centre.
I believe that the A320 for much of the distance between Woking and the outskirts of Guildford has a shared pavement you can cycle on, but I've never felt interested in using it, for the Woking - Slyfield section because on-road via Sutton Green is clearly much nicer than cycling on a pavement, and for the Slyfield - A25 section just because it's so horribly disjointed:
Here: https://firstname.lastname@example.org ... 312!8i6656
cycle on the road
cycle on the pavement (prohibited here I think) and turn left (where cycling is then permitted), cross via the toucan crossing, turn right and then there is a pavement separated from the road which is just visible on the other side of the junction.
Then you get to this junction:https://email@example.com ... 312!8i6656
Where you can cycle across using the road as a car would do
OR, cycle on the pavement and head left and cross at the side road before heading up this alley way, which leads to a road parallel to the main road separated only by a row of trees https://firstname.lastname@example.org ... 312!8i6656
The main road and the parallel road both emerge at this roundabout, where you can once more continue straight ahead on the main road, or head up here: https://email@example.com ... 312!8i6656
where you are thrown into a bus lane or could (illegally I think) continue on the pavement
This continues to this hostile multilane junction https://firstname.lastname@example.org ... 312!8i6656
Which is shortly followed by anotherhttps://email@example.com ... 312!8i6656
From there it's a procession of traffic lights on a single-lane 30mph road into Guildford. AFAIK cycling is not permitted on the pavement from that point.
So you have a choice in terms of cycle 'infrasructure' of:
a random selection of disjointed bits of pavement and residential roads, which don't proceed in a straight line and which end abruptly short of their destination whereupon you can just cycle on the road like a car, or be a pariah on the pavement
just following the car route the whole way (and being abused by motorists)
The challenge for the cyclist is knowing when the cycle infrastructure will get them where they are going, rather than perhaps a small portion of their journey. In the case of the Sustrans routes it is presumably the case that there is an end-to-end route, but you never quite know if it would be preferable to use roads for some sections. In the case of 'shared pavements' more generally, the presumption for me is that they are useless until proven otherwise - perhaps ok if you are cycling a mile to the shops, but unlikely to be worth using for a journey of say 5 or 6 miles.