rubberneck

Short definition from Wiktionary

Noun

1. 1
   Someone who engages in rubbernecking, or turning and staring.
2. 2
   A tourist.
3. 3
   Someone or something with a flexible neck.

Verb

1. 1
   To watch by craning the neck (as though it were made of rubber), especially if the observer and observed are in motion relative to each other.
2. 2
   To cause (someone) to watch in fascinated horror, as if rubbernecking to see a roadside accident.