@MediumDave: Went round the Pentlands for a bit (very quiet once away from the roads). A while later I came back through Blinkbonny and counted the cars again. The number had more than doubled!
The other day my walk took me up past the Braid Hill golf course clubhouse. The sizable parking area in front was not closed off in any way. A fair number of cars were parked there including two from which dogs were being unloaded, clearly preparatory to being walked on the golf course.
Although I perviously suggested that spot-checking folks on the golf course itself would likely reveal mostly locals, it would surely be a simple job for the polis to hang around such a large and apparently well-used parking area to have a quiet word with people obviously not complying with the "don't drive to exercise" guidance.
And again, Braid Hills Drive had a number of cars parked at the side here (where the verge is getting cut up quite badly after the recent rain) and in the layby near the now-closed-off ex-doggers' car park. And there are always a few cars parked up on Braid Road by the access to the Hermitage driveway.
Based on observations locally, therefore, I increasingly get the impression that the "don't drive to exercise" guidance is not being enforced inside the City Bypass.