On Cairo's Metro, women have the choice of sharing carriages with men or travelling in carriages reserved only for them. It is a unique place that offers a window into life in Egypt's capital, as BBC Arabic's Dina Demrdash reports.
The last time I took a women-only carriage on the metro was seven years ago.
Some things never change. It is still the same chaotic, crowded space and the air still sits heavy with dust, sweat and perfume.
The carriages have always been a favourite for vendors, who sell everything from tissues to hair accessories and mobile phone top-up cards.
But some things have changed a lot.
It is past midday and many of the faces I see look tired. But the talk is far from weary, and is about topics you would have barely heard a few years ago.
At first, I cannot find a seat but do manage to stand next to two girls. I gather that they are students at the university near the station.
"It took me half an hour to get in [to university]. It was crazy," one of them says with a muffled giggle. "What's all this about?"
Cairo is obsessed with security these days.
It is becoming common to wake up to the news of bomb explosions blamed on Islamist militants opposed to the rule of President Abdul Fattah al-Sisi, who as army chief overthrew Egypt's first democratically-elected leader Mohammed Morsi in 2013.
Most of the bombings have caused only small numbers of casualties, but they have led to Cairo becoming more congested.
The metro is even busier now, as people try to escape endless roadblocks above-ground.
"I worry for my children every time they go out," says a woman with a colourful veil sitting a few seats away.
"You know there were bombs found here in the metro?" a woman next to her adds. "May God have mercy on us."
Bread and politics
The carriage serves as a window into wider issues in Egyptian society - including one which is not so new.
"I bought three kilograms of tomatoes for 10 [Egyptian pounds ($1.31; £0.87)]," says a woman in her 50s, also veiled.
Her companion, who carried a plastic bag of groceries, nods in agreement.
"Check this out," she says, pulling out of her bag a loaf of light brown bread. "This, for 25 piastres ($0.03; £0.02)! Look how small it is!"
They then turn to Egypt's favourite topic of the past four years: politics.
"What elections? Let them stop these bombings first," says the first woman.
Voting for Egypt's parliament - which was dissolved in 2012, shortly before Mr Morsi came to power - was due to begin on 22 March.
But the Supreme Constitutional Court ruled on 1 March that part of the election law was unconstitutional, meaning the polls will likely be postponed by several months.
"My son dragged me to vote last time. What good did it bring?" the veiled woman complains.
"As if everything is sorted now except the parliament," her companion says.
A young woman standing nearby gives them a disappointed look, then turns away.
Not long afterwards, scuffles erupt at one end of the carriage.
"I do not have to tell you why you have to get out!" a young woman shouts at a middle-aged man who is trying to get on. "This is not your place, it's for women!"
He backed out of the carriage quietly.
Women-only carriages on Cairo's Metro were introduced in 2007, when Egypt saw the first signs of what is now considered an "epidemic" of sexual harassment.
Women used to board the women-only carriages to escape inappropriate stares or comments. But it can get much worse these days.
More than 99% of women and girls in Egypt interviewed for a survey published by the UN in 2013 reported that they had experienced some form of sexual harassment.
And women's rights groups say hundreds of women have been raped or sexually assaulted in public by mobs since the overthrow of President Hosni Mubarak in 2011, many of them at demonstrations around Cairo's Tahrir Square.
As the train approaches its final stop some women collapse onto now empty seats.
"We should have one or two more carriages," says one of my fellow travellers with a sigh. "It is not asking too much to breathe, is it?"