Commercial activity needs to be kept in its place. Most merchants would agree with that — particularly those in the majority, who pay for the place in which they do business.

And the space for that business, with few exceptions, should not be on the sidewalk.

The trouble is, where there’s money to be made — and there’s lots, in Waikiki — people will find a way. This compels government to assert some control over a situation that can be a nuisance to many and unfair to businesses that are pulling their freight.

Thankfully, the city seems inclined to act on a situation with wheeled vendor kiosks on Kalakaua Avenue that is getting out of hand in Honolulu’s primary tourism destination.

City Councilman Trevor Ozawa, who represents Waikiki, is working with the Waikiki Improvement Association to write a bill that would tighten restrictions against this practice in the city’s public- nuisance ordinance.

Among those complaining to the association are brick-and-mortar business owners chagrined to see these rent-free operations promoting their businesses from rent-free carts.

The objective of legislation is clear: to prohibit this, regardless of whether the sales activity takes place from a kiosk on wheels, and whether or not money changes hands on the spot.

The Department of Planning and Permitting indicates that enforcement under current law would require that the kiosks be a fixed structure rather than mobile. The Honolulu Police Department points out the requirement to comply with city peddling laws that call for a permit and sets limits on the size of the sale structure and other factors.

There has been a recent increase in the number of these kiosks, however — up from one or two to eight or nine — and in the complaints about them. These are coming not only from the established merchants, who are understandably annoyed that these vendors may be steering business away from them, but from tourists as well.

For example, attendees at the Duke’s OceanFest, held Aug. 19-27, found it all quite irritating. This does anything but enhance the visitors’ experience.

Land use rules are often tailored to Waikiki because its success is central to the state’s bedrock industry. There are specific development regulations and ordinances such as the sit-lie ban that apply to select zones. It would be warranted to make a new regulation particularly firm within a special district.

Of course, some of the more aggressive sales tactics may be a response to other regulations, such as the restrictions on signage, guidelines that were more recently relaxed for better visibility. But there’s too much at stake to let this problem continue to fester.

One concern is public safety. The sidewalk is meant for pedestrian passage, and kiosks tend to intrude on that space.

It’s also a matter of fairness to business. The reason it’s so tempting for merchants to peddle their wares and services in this way is that there’s a lot of money to be made and rents are sky-high.

Regular shops in Waikiki pay anywhere from $15 to $35 per square foot to rent their space on Kalakaua Avenue. It ranks No. 5 nationally among shopping streets for its sales volume, said retail analyst Stephany Sofos.

And landlords renting paid kiosk space pay $5,000 to $25,000 a month.

So the incentive to skirt the law and avoid this cost is plain enough, and that motivation must be countered by strict rules.

If such steps are not taken, the ambiance of Waikiki will continue to decline. Instead of a pleasantly engaging walk along a bustling seaside avenue, visitors will contend with frequent interruption and the tackiness of vendors who should be conducting business in established locations they’ve secured with their rent payment.

And if that happens, city leaders will have only themselves to blame.