Discription of Events: Med.length, dark-haired teen or early 20-something driver, distracted, on phone, very eratic speeds. I passed so as to keep up with of speed of other traffic traveling abt 78 to 80 mph. Driver then apparently took unbridge at being passed, chose to accelerate RAPIDLY to 90+ mph in a very short area of interstate driving right up to back of a clearly slower moving vehicle then aggressively swerving right directly at my right front bumper forcing me to swerve left half off the lane into median to avoid collision in bumper to bumper interstate travel. Driver then cut back in front of me WITHOUT space between me and car in front of me next forcing me to slam on brakes (apparently driver's objective)...this dangerous decision caused same chain reaction behind me in 5 O'clock-rush hr interstate travel. Driver continued speeding, tailgating, weaving in/out lanes & columns of traffic causing grossly unsafe conditions for dozens drivers for next 5 miles. Then at next major 1-12 merge site (at so. bound 190 merge with 1-12 west bound) this very clearly distracted or possibly impared driver was forced to SLAM on brakes and leave roadway to avoid high-speed rear end collision because traffic was backed up, being rush hr and all yet this irresponsible driver with ZERO judgement is exceeding speed by atleast 15mph. This 2nd instance caused another chain reaction among multiple vehicles. There was atleast 2 passengers in car who were insane enough to risk their lives traveling with this moron. Dead is forever! If someone ELSE is paying insurance for this driver, you want to rethink your investments and personal property. Likely to kill someone who is sure to sue you.