Travelers arriving in Massachusetts, such as by train to Boston’s South Station, must have negative test results for coronavirus or quarantine. (Photo: The West End via Flickr)

A new state travel order covering people who visit or return to Massachusetts from most states took effect Saturday. As the hospitality industry opens up in Cambridge, it’s not clear how the requirements are being enforced.

The order calls for travelers, including those returning to the state, to produce a negative coronavirus result from a viral test within the past 72 hours, or quarantine for two weeks. It originally exempted those coming from the other New England states and New York, New Jersey and Hawaii because of their low rate of infections; this Friday travelers from Rhode Island will no longer be exempted. Other exemptions include people traveling through the state to another destination, people commuting to work or school, those coming for medical treatment, essential workers and military personnel ordered to Massachusetts.

Most others, including college students returning to campus, must fill out and submit electronically an online form attesting that they are complying; they can be asked to prove it, according to the order. Violators can be fined $500 per day.

When the order was announced on July 24, Gov. Charlie Baker said local health boards and departments as well as the state Department of Public Health would enforce it; he also said he expected “the honor system” to work in the majority of cases. The order says lodging operators are expected to tell guests of the requirements; websites of some but not all Cambridge hotels include a link to the order, but those with no obvious information might still tell travelers about the requirement when they reserve or check in. A check of four random Airbnb advertisements for apartments in Cambridge did not mention the order, but potential renters might be informed when they reserve.

Susan Feinberg, spokeswoman for the Cambridge Public Health Department, said Thursday that the department believes “based on language in the order” that the state health department “is the lead agency for enforcement and may assign local agencies, including local health departments, to assist with enforcement.” As of Thursday the state agency hasn’t contacted Cambridge about enforcement, she said. Another online state form posted Tuesday allows residents to complain about violations of any public health rules, and Cambridge would follow up if requested by the state, she said.

State health department spokesman Omar Cabrera did not respond when asked what the state would do with the submitted travel forms and whether they were being forwarded to local departments.

A report in the Vineyard Gazette on Saturday quoted a local health agent as saying the state is sending the travel forms to local health boards and departments to tell them who must quarantine. The day before the order took effect, Baker said 8,000 travelers had already submitted forms, according to a report in the state news site MassLive. Feinberg said the Cambridge health department had not received any travel forms as of Wednesday.