On Qasr-al-Nil bridge, leading to Tahrir Square, the cars honked their horns in a vain attempt at unison, children leaned perilously out of the windows waving Egyptian flags, and young men dodged, danced and ran along in gleeful celebration.
Small boys clambered onto tanks to be photographed by their parents; others insisted on having their mobile phone pictures taken clasping the hands of the slightly embarrassed soldiers.
Over on the Nile Corniche, where thousands of Egyptians poured off the 26 July Bridge to join the young people marching down the road past the TV station, they chanted: "The people, at last, have brought down the regime."
You could see a taxi so overflowing that two men were draped on its side, clinging to the roof rack and shouting that they had won.
One family, the mother dressed in traditional head covering and abaya, had commandeered for their triumphant journey home a horse-drawn open carriage, of the sort only a tourist would be seen using in normal times.
But there were no tourists, and these were not normal times. A mere 20 minutes earlier, in the tersest possible of statements, Vice-President Omar Suleiman announced on state television that Hosni Mubarak's dictatorship was at an end.
Completing the victory for the people, he added that the army, and not Mr Suleiman himself would be responsible for what every protester on the streets last night hopes will be a transition to true democracy.
"Taking into consideration the difficult circumstances the country is going through, President Mohammed Hosni Mubarak has decided to leave the post of President of the Republic and has tasked the Supreme Council of the Armed Forces to manage the state's affairs. May God help us in our steps," he said.
But despite the confirmation earlier that Mubarak had left for his retreat in Sharm el Sheikh, few had expected the announcement. After Thursday's disappointment, hundreds of thousands of Egyptians responded by yet again packing Tahrir Square yesterday, with thousands then marching – peacefully if noisily – out of the square to the television station, which was heavily defended by troops, tanks and barbed wire.
The protesters also marched on the presidential palace, 7km away in Heliopolis, as the revolution continued to create its own dynamic momentum – perhaps it was that that persuaded the army to finally put an end to Mubarak's rule.
The army had also issued a cryptic statement earlier in the day implying that it would be responsible for ensuring the implementation of the constitutional and political reforms that Mubarak had pledged in his television speech.
Yesterday morning, one of the uprising's young organisers, Gigi Ibrahim in Tahir Square, said of Thursday night's speech: "He is goading, aggravating us now. Why doesn't he get the message and get out, and Omar Suleiman with him?" Another protester, Ibrahim Hadda, a 23-year-old student, had complained: "We think the army is on our side, but what are they waiting for."
The sheer surprise of Mubarak's precipitate departure reinforced the sense of triumph on Cairo's streets last night. "I am born today," said an ecstatic hospital worker, Sharif Mohammed, 33, a bandage still covering part of his badly bruised face from the clashes with Mubarak supporters last week. "Don't worry, it was worth it. I am going home to celebrate with my family. I have got my freedom in Tahrir Square."
Zeina Hassan, a graduate student aged 26, said: "We just didn't expect this today. I was in the crowd outside the television station and actually I was pretty down after Mubarak's speech and all this tit for tat involving the government and the army.
"No one was ready for this happening today. What is so great about this and has truly empowered the people is that I feel no one will be able again to take advantage of the system any more because all we will have to do is go out again and stand side by side believing in our cause."
Ms Hassan, an Egyptian who on 27 January had flown from Beirut, where she studies at the American University, to join the daily protests, said she came home "because I had to be part of it. It was almost all peaceful – the aggression was on the other side, and that says a lot about the way the revolution was organised and a lot about Egyptian culture. All the religions have been together, Christian, Muslim and secular, and it has brought Egyptians much closer together, which is beautiful."
Omar Mohammed, 33, a petroleum engineer and another daily participant in the protests, said: "I feel so proud of the Egyptian people. I thought there might be a revolution led by the poor and the Muslim Brotherhood, but it wasn't – it was led by the young generation on Facebook and Twitter, but it will help the poor because they have never had their rights. Egypt is full of economic resources but they have never had their share because there is a lot of corruption."Reuse content