A recovery in rail passenger satisfaction is fragile and under pressure, a transport watchdog has warned.
Some 83% of people were satisfied with their last train journey according to Transport Focus' spring survey of 27,000 passengers.
This is an increase of three percentage points compared with the same period last year and is the joint-highest figure since autumn 2012.
Satisfaction with punctuality and reliability of services rose from 73% to 77% in the past year, and overall satisfaction for passengers in London and the South East improved from 79% to 82%.
Southern Railway - which has been engaged in a long-running row with unions over staffing and driver-only trains - recorded the lowest overall score of 72%, up from 69% last year.
No train company's satisfaction figures declined.
Transport Focus chief executive Anthony Smith said: "These green shoots are fragile and need nurturing.
"This recovery will be under pressure from upgrade works, industrial relationship problems and rising passenger numbers. So the industry needs to keep a relentless, ongoing focus on performance and reliability."
The improvement in Southern's performance was boosted by increased satisfaction with the availability of on-board staff and staff at stations, Mr Smith said.
He added: "There is some way to go to reach a more acceptable position. Southern, Thameslink, Great Northern and Southeastern have the lowest scores."
Jacqueline Starr, managing director of customer experience at the Rail Delivery Group, representing train operators and Network Rail, said: "Rail companies are working together to make journeys better and we are pleased to see more satisfied customers.
"There is more to do which is why we are investing to improve and better connect communities across the country with major upgrades to the rail network, thousands of new carriages coming on track and 6,400 extra services a week by 2021.
"We will also continue to work hard to provide better information to our customers, simpler fares and a more accessible railway for all."
Labour's shadow transport secretary Andy McDonald claimed it was "disappointing but not surprising" that passenger satisfaction "remains low".
The only category to suffer a decline in satisfaction was personal security on trains - down two percentage points to 75% - although Transport Focus said the figures "may not be completely comparable with previous waves" due to changes in question ordering.
Mr McDonald added: "The results reveal a concerning decline in passengers' sense of personal security, bringing into question the Government's policy of de-staffing and de-skilling the railway.
"With fewer than half of passengers finding value for money in the price of their ticket, it's becoming more difficult for the Government to justify allowing private and foreign state-owned companies to take money out of the system that should be used to improve services or hold fares down."
Mick Cash, leader of the Rail, Maritime and Transport union, said: "These are marginal increases in satisfaction from an abysmal base and coming at the time that key electrification and upgrade works are being cancelled, passengers and staff will be rightly cynical.
"The only solution to Britain's private rail rip-off is public ownership."