US aviation regulators say they’ve made progress reducing the risk of flight disruptions from new 5G service that’s set to start January 19, but are still releasing scores of potential limitations across the country.

       The Federal Aviation Administration expects to provide information soon on what percentage of aircraft will be subject to the restrictions, the agency said in an emailed statement Wednesday. At midnight, it will release so-called notices to air missions or Notams spelling out new prohibitions at hundreds of sites.

       The FAA “has made progress to safely reduce the risk of delays and cancellations as wireless companies share more data and manufacturer altimeter testing results arrive,” the agency said in the release.

       AT&T Inc. and Verizon Communications Inc. reached a compromise with U.S. officials last week, agreeing to delay their 5G service for two weeks and to limit placement of cell towers near 50 airports for at least six months.

       While the companies have said their new service poses no risk to aviation, the FAA and aerospace-industry groups say tests show devices that calculate altitude could become unreliable if aircraft get too close to cell towers.