A city that limits its visitors has usually run out of quieter options first

The problem is concentration, not numbers

A city can absorb a great many visitors if they are spread across its area and its calendar. What causes difficulty is when a large share of them want the same three streets, on the same afternoons, in the same four months, because the capacity that matters is the capacity of a bridge, a square or a single narrow lane rather than of the city as a whole.

This is why headline visitor totals are a poor guide to whether a place feels overwhelmed. A town with modest annual numbers and one famous viewpoint can be far more congested at the point of contact than a large capital that receives many times as many people spread over a wide centre.

Concentration has been increasing for reasons that have nothing to do with tourists behaving differently. Cruise itineraries deliver several thousand people within one window, cheap flights cluster around weekends, and photographs circulating online make specific spots famous in a way that guidebooks never quite managed.

The residential effects arrive before the crowding does

Long before a street feels full, the composition of the buildings on it changes. Flats become short-term lets because that use earns more, ground-floor shops turn over to serve visitors rather than residents, and the ordinary infrastructure of living somewhere — a hardware shop, a doctor, a school with enough children — thins out.

That process is self-reinforcing, because as residents leave, the customer base for everyday businesses shrinks further, and the remaining premises are worth more to a use aimed at visitors. Historic centres in several countries have lost a substantial part of their resident population this way over a few decades.

The politics of this are sharper than the politics of crowding, because it is about housing. A city can tolerate busy streets almost indefinitely; it cannot easily tolerate its own workforce being unable to live within reach of the jobs, and that is generally what turns a grumble into policy.

The measures come in a fairly predictable order

The first responses are soft: signage, campaigns to spread visitors to other districts, promotion of the shoulder season, and codes of conduct about noise and dress. These are cheap, uncontroversial and have modest effects, which is why they are rarely the last step.

Then come measures that shape flow without stopping it: timed entry to major sites, restrictions on where coaches may stop, one-way systems on famous bridges, limits on group size and on guides using amplification. These work reasonably well at the specific point of pressure and tend to move the problem a street away.

The hardest measures are regulatory or fiscal: a tourist tax, a cap on cruise calls, licensing of short-term lets, and in a small number of cases a charge to enter the historic centre on peak days. These have real effects on behaviour and real opposition from the businesses that depend on the current pattern.

None of it is settled, and the objections are serious

A charge to enter a city raises an obvious question about what a public street is, and it is not a question with an agreed answer. Restrictions on letting are contested by property owners; caps on cruise calls are contested by ports; taxes are argued about on the grounds that they deter the modest visitor and not the wealthy one.

There is also a fairness problem that nobody has solved. Measures that raise the cost of visiting tend to filter by income rather than by behaviour, so the outcome is a quieter city visited by richer people, which is a different city rather than a fixed one.

And places genuinely disagree about the goal. Some want fewer visitors, some want the same number spending more, some want the same number spread differently, and the instrument chosen depends on which of those a council has decided it is aiming at.

What a traveller can actually do about it

Almost all of the pressure sits in a small area during a small part of the day and year, so the useful adjustments are equally specific: go early or late rather than midday, stay a few streets outside the designated centre, use the third-best example of whatever the city is famous for, and give a place more days rather than one.

Booking a licensed room rather than an unlicensed one is a more direct contribution than it sounds, because the licensing rules are precisely the mechanism the city has chosen. Where a tourist tax exists, it is worth knowing that it is generally hypothecated to exactly the costs visitors create.

And the most effective single choice is usually the calendar rather than the destination. The same city in a month either side of the peak is a substantially different experience for the visitor and a materially lighter load on the place, and it is the one decision that does not require giving anything up.