I wanted to spot a city truck this morning on the expressway at approximately 8:25 am (the kind of truck that has the large lane merge flashing light on the back of it). You merged onto the expressway at full speed from Central into high speed traffic and slammed on your brakes to block traffic in the left lane, not taking into account the vehicles you pulled out in front of that were travelling at 100 km. Myself and the vehicle in front of me had to slam on our brakes, almost having to swerve off the road into the ditch. You are lucky you didn't injure anyone or worse, kill anyone. I wish I had got your license plate, however I was driving and too shaken up to take it down. Next time wait for traffic to clear before abruptly stopping on the expressway. Please watch your driving!!!