Traffic Idioms (American idioms) 美 式交通的慣用語
explanation : This common idiom refers to the part of the car called
the 'bumper' in the front and rear of the car. It means that traffic is so slow, the
bumpers of the cars are almost touching. In other words, traffic is almost stopped.
e.g. In Los Angeles, the traffic on the freeways is always
bumper-to-bumper at 5:00 pm.