I'm afraid that this is going to be something of a rant. I get increasingly annoyed by the way in which we seem to be imitating the US in designing our urban spaces around cars, with little regard for people who might prefer to (or have to) walk. I know that some cities in the US are quite pedestrian-friendly, but others just assume that you have a car and use it for even the shortest of trips. I'm used to walking around unfamiliar towns, and remember the bizarre looks I got in San Diego when I asked for directions for walking from one place to another.
Instead, you have to continue on this pointless path (which after all, just runs parallel to the pavement of the main road) until you reach the access road. You then have to follow the route that cars take, until you reach the entrance to the car park, whereupon the pavement abruptly stops. Then you have to dodge the incoming cars whose drivers are so intent on purchasing that vital Marks and Spencer ready meal that they fail to notice your presence. In total, I reckon that you're made to walk an extra 300-400 m over the most direct route, in pedestrian-unfriendly conditions.
Why then, you're probably thinking, don't you just climb down the bank and hop over the fence? Of course, that's what I generally do, unless I'm laden with shopping. Judging by the informal path worn in the grass leading to that section of fence (a 'desire line' in landscape architects' terminology), that's what a lot of other pedestrians do too. If you're a smart architect, you pay attention to desire lines, because they show you very explicitly where people want to go. It would be so easy and cheap for them to extend the existing path a few metres, open a small section of the fence and put a few steps (or better still, a ramp) in to reach the shops, but apparently pedestrians aren't worth that kind of consideration any more.