I am searching a word for describing cars stuck in traffic. When I googled the phrase "stuck cars", I found out that stuck cars imply cars stuck in ditches rather than traffic.
I don't know what exactly you mean by an abbreviation, but in English, a situation when there are just too many cars on the road where little to no movement is possible is traditionally called a traffic jam or a traffic congestion. To find out more about what other expressions related to cars stuck in traffic exist in English, follow the link to the Wikipedia article on traffic congestion that I provided.
The reason I'm so late today is because my car got caught in a huge traffic jam this morning.
You could say, "Heavy Traffic", "Congestion", "Clogged Roads", "Heavy Delays", or, even depending on the cause, you could say, "Gaper's Delay" or "Rubbernecking" if the cause is because people are staring at an accident. You could also say, "Traffic was at a standstill", or call the highway "A parking lot".
You can use gridlock or deadlock. It is defined by Oxford Dictionaries as follows:
A situation of very severe traffic congestion.
‘the city reaches gridlock during peak hours’