Euro organizers installed special traffic lights to help control the numbers of fans on a bridge taking supporters across the River Aar in Berne ahead of the Holland-France match, it was reported Saturday.
A red light meant sit down, orange that they could stand and green they could move forward, Swiss radio stated.
Marshals carefully choreographed the throngs of supporters ensuring the lights were strictly obeyed to avoid overcrowding, dpa reported.
"You will never see anything like this again," said one Dutch fan.
More than 100,000 fans turned out to watch the showdown, around 50,000 of whom were Dutch.
An extra screen was installed at Kornhausplatz where 15,000 people could gather and was filled to bursting. The two other fan zones in the city taking 25,000 people were also full.
In Zurich, where Italy met Romania, around 70,000 supporters gathered with up to 35,000 people using the fan zones.