For information about Closures from Penndot, please click on your Penndot engineering district and then on roadwork PennDOT Engineering districts
The 511PA website is also a good source of information about current closures.
Pennsylvania should follow the US Standard for Road Closures or Major/Long Term Construction projects. Please see the US Construction Zones & Road Closure Wiki for information regarding closing & flagging roads in the editor that are under construction or closed.