Ah, Paris in the spring. It's even lovelier if the trip to Europe happens to come free.

But if the hosts may be selling a transit system to Honolulu and the guests are politicians who could be buying it, free trips aren't quite ethical.

The City Council is set to vote tomorrow on the first segment for transit system construction, and will take up an offer from Phileas Advanced Public Transport at that meeting or thereafter.

If it aids in the decision-making process, then the council should accept the Phileas invitation to visit France and the Netherlands to look at the company's bus system, which could be used in Honolulu's fixed guideway system. But the city should pick up the check, rather than treat the $7,500 in travel expenses as a gift.

That's the best way to resolve this specific quandary, to avoid even the appearance of corruption. But as the city embarks on planning for a multi-billion-dollar transit system, elected leaders — the mayor as well as the council — will need a clearer policy for handling the travel opportunities that are sure to come up. Criteria should be set to determine which trips are necessary.

To date, the practice has been to treat travel "junkets" as gifts to the council, which then would tap a select group to take the trip. Councilmembers already have taken some trips in the past year, some underwritten by private companies, others on the taxpayers' dime. But that casual approach is sure to pose problems as the transit selection process accelerates. At this point, councilmembers will be narrowing the search for the system that we will buy.

The city should pay for these trips, and travel budgets should be set aside now to cover trips, by the legislative and executive branches.

The taxpayers are counting on decisions on such an important project to be made on the facts, and any factors that could curry their favor should be taken out of the mix.