This "don't travel" rule is self defeating. I live within 5 minutes walk of a shore. Unfortunately, because there are five multi-storey flats nearby and some multi-storey luxury flats about 5 minutes in another direction, so a few thousand other people also live within a short walk of that shore. So if I go there, it is inevitable I will be near hundreds of other people.
On the other hand, if I drive up to ten miles, there are dozens of places I could go where the chances of meeting more than two people is tiny, and the chances of meeting no-one at all quite high.

Unfortunately similar reasoning is being used by those who live ten miles away who want to have a walk by the shore.

Just a couple of days ago police fined two women for driving from Leicestershire to Derbyshire to meet-up for a walk. The police (apparently) said that as they'd taken coffee with them it was a 'picnic'.
Far be it from me to disagree with the police, but I think these two women were "a couple of sandwiches short of a picnic".