The world's worst underground train lines: From 'filth' in the UK to crime hotspots in New York and overcrowding in Tokyo

While handy for whizzing from one end of a city to the other, underground train networks certainly don't all run smoothly – whether it's major delays or filthy carriages causing upset.Here in the UK, London's underground network is no stranger to such complaints; both the Northern and Central Lines in particular are criticised for their 'appalling' conditions. Over in Europe, one line on Paris' Metro is often 'packed-to-the-brim', according to passengers, while New York's Subway is renowned for being both dangerous and dirty.Here, we look at some of the worst underground train systems around the world – and where you might want to catch the bus instead... London's Northern and Central lines London's Central (pictured) and Northern line received the most complaints about the conditions of their carriagesMore than 4million passengers use London's Tube service daily, whether for work, to tour the capital or to simply get around. Some lines, however, perform worse than others. The Northern and Central lines are the most complained about across the entire network, according to FOI data collected by TimeOut.The two made up more than half of total complaints – 307 and 251 respectively – about poor carriage conditions between 2023 and 2026. Passengers' experiences of the lines supports the figures, and one person wrote on a Reddit post asking which line has the dirtiest seats: 'Northern line front carriage has some horror shows'.'Northern is the worst I've seen,' someone else wrote. 'I don't travel it often but last time I did I took the only photo I've ever taken on the underground to show my wife how appalling it was.'Budapest Metro Budapest Metro has been dubbed the worst in Europe in a previous studyPreviously named the worst in Europe, Budapest Metro might connect millions of visitors across the capital – but it has received some scathing reviews online.Luggage storage website Bounce released The Underground Index in 2024 and considered factors including the average Google review score of stations, the distance covered, the number of stations, the annual ridership, and the percentage of positive and negative online reactions to news about each metro.Budapest's underground network has 48 stations across four lines – a relatively small number given the 382million passengers who use it each year.It managed to score a respectable average of 4.05 out of five, but 75 per cent of online reactions to articles about the system were negative.New York City Subway's Lexington Avenue line New York City Subway's Lexington Avenue line has been described as 'an absolute nightmare'When exploring the Big Apple, visitors might want to be mindful which subway line they take to get to their next sightseeing stop. Research by urban policy think-tank Vital City found the stations with the highest number of violent crimes are along the busy four, five and six lines on Lexington Avenue, Bloomberg reported last year.Aside from crime, passengers have expressed how busy the line can become too.'As a daily rider of the Lexington Avenue Line, I can attest that the 6 is an absolute nightmare during rush hour, especially at express stations,' one commuter wrote on Reddit. 'The crowding is beyond insane. I really don't like trying to fight my way into the car, getting pushed out by the overflow, and waiting 10 minutes for multiple equally packed trains to pass while I stand on the platform waiting like a weary chump.' Tokyo Metro Tokyo Metro has been described as 'packed like sardines' during its peak hoursWith millions of people calling Tokyo home and millions more visiting each year, it's no wonder its metro system can feel overcrowded.One tourist recalled their experience on Reddit: 'Having done peak hour in Tokyo only once (around 7am) and it was only about 6 stops on one subway line, I can say, with certainty that it's packed.'As in, “packed like sardines” packed. People were so squished together that even if the train braked hard, I literally wouldn’t move packed. And the friends I was travelling with (who live in Tokyo) told me that this was just everyday life for them.'This was the Tokyo Metro, though so I reckon it probably was still nowhere near as bad as say, the JR Chuo Line which is a major arterial line servicing the suburbs of Tokyo. That particular line is super busy even outside of peak hour so I can only imagine how bad it would be during peak hour.'Outside of peak times, Tokyo Metro lines go from: easily able to get a seat to standing room only but not packed at all.'Paris Metro's unlucky line 13 and 8 Line 13 on Paris Metro has been described as 'packed-to-the-brim' by passengersCertainly unlucky for some, Paris Metro's line 13 has built up a poor reputation over the years and is widely considered the 'worst' across the network. Regular passengers described it as 'packed-to-the-brim' to Paris Secret, and commented on its slowness in comparison to other lines. When Line 13 partially closed over the summer, the publication wrote how it was 'going to be living hell' due to the chaos that would ensue on the already busy stretch of track. Yet despite widespread issues with Line 13, it was instead Line 8 recently dubbed the 'worst' by Parisians. They complained about it being 'very long' and slow, as well as quite unreliable at times too. São Paulo Metro São Paulo Metro, in Brazil, has some lines which see more mechanical failures than othersBrazil's São Paulo Metro officially opened in 1974, and connects locals across the city – but it isn't always perfect.Line 3-Red is apparently the worst on the network, particularly between Palmeiras-Barra Funda and Corinthians-Itaquera, according to a survey by TV Globo, São Paulo Secreto reports. The research considered the number of mechanical or technical failures in the first half of 2026 and found Line 3-Red came out as the poorest performer, with a total of 28 incidents.Line 7-Rubi saw 21 failures, followed by Line 8-Diamante with 20. However, 3-Red did see some improvement compared to the same period last year, when it experienced a total of 41 technical incidents.