April 20, 2012:
On April 15th North Korea held a military parade, and one of the vehicles displayed was a 16 wheel TEL (Transporter Erector Launcher) carrying what appeared to be a three stage ballistic missile. What was interesting was the TEL, which is an unusual vehicle specially built to carry, then erect and survive the launch of a ballistic missile. The North Korean TEL was unlike any seen before but the cab was similar to a Chinese heavy transporter. North Korea may well have bought these heavy trucks and then modified them into TELs. This is what Iran did for a long time, until sanctions officials ordered heavy truck manufacturers to stop selling Iran the big vehicles that could be converted to TELs by the buyer.
Large trucks modified to be TELs are often not real TELs. There are a lot of manufacturers out there who build huge (12-20 wheel) trucks, and these are often used to carry military equipment (like 60 ton tanks). A 12-50 ton ballistic missile is no problem but installing the hydraulic gear and controls to erect the missile to a vertical position is tricky. Even more difficult is hardening the rear of the vehicle to minimize the damage from the rocket exhaust. This last bit can be dropped if you only expect to use these TELs once for a live fire. The 16 wheel North Korea TEL may have been one of those "use once and abandon the trailer" models.