"serious congestion" is correct and usable in written English.
You can use it to describe a situation where there is an unusually large amount of people or vehicles in a particular area. For example, "The city was experiencing serious congestion due to the influx of visitors for the holiday weekend."
That caused serious congestion on rural highways and several wrecks.
Duckenfield did not tell Kelly that, in fact, he had ordered the gate to be opened, at 2 52pm, to alleviate serious congestion outside the turnstiles to the Leppings Lane end.
In his previous day's evidence he accepted he made a "serious mistake" when he failed to foresee where fans would go, after he allowed hundreds in by ordering a large exit gate to be opened to relieve serious congestion outside Hillsborough stadium's Leppings Lane end.
If not controlled properly, they may collectively result in serious congestion.
With the increasingly serious congestion of the highway, it is very important to get the accurate traffic jam by the means of information technology.
The excessive multi-copies spraying in the network causes serious congestion and exhaust nodes' buffer space, thus influences the performance of transmission dramatically.
Teixeira, who has been wracked by the cough for about a month, said he was found to have nothing more serious than severe congestion in his bronchial passageways.
INSIDE PITCH Mark Teixeira, who has been wracked by a cough for about a month, said he was found to have nothing more serious than severe congestion in his bronchial passageways.
To others, though, it is a forward-thinking solution to the capital's serious traffic congestion.
As well as causing flight chaos, with many services either cancelled or diverted, the shutdown led to serious road congestion which spread to the nearby M1 motorway.
The city began building its subway in 1972, and by 1979 the first station was opened as an initial step in the development of an underground system aimed at alleviating Rio's serious traffic congestion.
