AUSTIN (KXAN) -- The Round Rock Police Department is responding to a major crash involving two vehicles, the agency said on social media Tuesday. Around 10:20 p.m., officers responded to the crash on northbound Interstate 35 near Greenlawn Boulevard, RRPD said. All northbound lanes are currently shut down, according to police. Drivers should avoid the area, as well as seek alternate routes. This is a developing story. Check back for updates.