I think the safest thing to do would be to park on the left and swing round at the bottom of the street when leaving but I don’t think it would be suspicious activity if a driver turned round on arrival. This of course is assuming they came in from the top end in the first place which we can’t be certain of.Honestly, I don't find the vehicles that suspicious. You pay for all-day parking if you're going to be gone all day, which says commuter to me, particularly given there's a mainline station 75 yards away. Trains are still coming in at that time of night. Not everyone works 9-5 and then comes straight home.
The van's unlikely to have been there all day because parking is restricted on that stretch until after 5pm, but it could be someone delivering to/picking up from a local business, visiting a local house, drinking in the pub on the corner (last orders at 11, drinking up til 11.30), picking up takeaway at the KFC round the corner on the main road (closes at midnight), popping into a convenience store somewhere near the station, etc etc. Lots going on all through the evening and somewhat into the night on the main road.
And I don't really see the closeness of the pedestrians to the van as suspicious either. That's how people cross roads in urban areas. If you followed the green cross code to the letter you'd never get across some roads. I can see why the police want to know if the driver noticed anything though.
The only thing I find slightly odd about the van is that, despite it being a no through road, it's facing up, towards the main road, as though the driver turned into the road and did a 180 before parking. I would think it more common to pull into a parking space on arrival (especially on that side of the road) and then turn around as you were leaving. But we haven't got a complete film here, and perhaps he did just that, then stood on his brakes to see what the pedestrians would do, which would explain the brake lights. (Or she, ofc.)
I think the van turns left at the top, which is a shame because the only traffic camera in the area is to the right, at the junction of London Road and Tamworth Road. I looked at the traffic cam images between about 11pm and 1am when the Derby Road cctv was released but the quality is too poor to identify pedestrians unfortunately.