European Union countries are trying to reach agreement on ways to ease pandemic travel restrictions within and into the bloc as leaders work to boost Covid-19 vaccination levels.

One option under discussion ahead of a two-day EU summit in Brussels is a plan to effectively scrap the traffic-light system of green and red areas in the bloc that has been used to govern travel rules and instead allow anyone who has been vaccinated to travel freely, according to a European Commission informal proposal seen by Bloomberg.

The plan would rely on the use of the widely adopted EU digital Covid passports, which have allowed travelers to cross borders without tests or quarantines since the summer if they can show they’ve been fully inoculated or recovered from the virus. Travelers without a Covid pass could be required to undergo tests after arriving in their destination.

“Given the very sizable impact on the exercise of free movement, persons traveling within the EU should in principle no longer be required to quarantine save for very exceptional situations (e.g. new variants of concern),” the European Commission proposal says.

Other jurisdictions have begun to open up rapidly in recent weeks after a slower start, with the U.K. simplifying its own traffic light system to a green and red list, with the latter now featuring only seven countries as of last week. The U.S., meanwhile, will admit vaccinated foreigners starting from Nov. 8, spurring demand on transatlantic routes that rank as the most lucrative for airlines and travel firms.

At the same time, there are some worrying Covid trends that could slow the push to relax the rules. Tuesday saw the most single-day confirmed deaths in Europe since April, with the 7-day average also on the rise. 

A second option proposed by the commission would retain the traffic-light system, but refine the data used to produce the ratings. Member nations would be encouraged to implement simpler and more standardized rules for handling travelers from red or grey zones.

The commission proposal would also maintain the use of the so-called emergency brake mechanism to be used to case of new variants of concern or outbreaks, but would aim to establish a common framework for when new restrictions should be triggered.