The eastbound lanes of Interstate 80 are closed in part of Columbia and Luzerne counties.
PennDOT said the interstate is closed between the Mifflinville/Mainville exit (242) in Columbia County and the Nescopek/Conyngham exit (256) after a crash and vehicle fire.
Police said two trucks collided and one jack-knifed and burst into flames. Neither driver was hurt.
Eastbound traffic is being detoured at the Mifflinville exit, to Route 339 to Nescopek, then back on to Route 93 to I-80 at the Conyngham exit.
Police are allowing traffic stuck on the interstate to pass the crash scene on the shoulder to clear the backup. PennDOT expects the crash to be cleared by early evening.
Drivers are urged to avoid the area.