People from Kings Langley pay more money per mile to commute to London than people living anywhere else in the region, according to a new report.
A weekly season ticket from London Euston costs £81.20 – or £3.87 for each mile of the 21-mile journey.
And research by independent passenger watchdog London TravelWatch shows that is around a third more than commuters traveling from other parts of the region.
Chairman Arthur Leathley said: “The current arrangements make no sense and are blatantly unfair to hard-pressed commuters.
“We have pushed for simpler fares for passengers in and around London for over 15 years, but the system is getting more and more confusing and unfair.
“Every time the fares increase by inflation, the gap between low and high fares gets even wider. That cannot be allowed to continue.”
Passengers from Tring, Berkhamsted, and Kings Langley were similiarly ill-served by the cost of a season ticket per mile.
A weekly season ticket from Hemel to London Euston costs £92.90 – equal to £3.79 for each mile of the 24-mile journey.
From Berkhamsted a £97.80 season ticket costs £3.49 per mile, while from Tring the £105.10 season ticket is the equivalent of £3.75 per mile.
However passengers from Oxted in Surrey pay £57.10 for a weekly season ticket that takes them 20 miles – only £2.86.
A spokesman for West Midlands Trains said: “Train operators inherited the present structure for regulated fares (including season tickets) at the time of privatisation in the 1990s.
“Subsequent increases have been subject to a formula set by the government each year. West Midlands Trains welcomes the Rail Delivery Group’s review of the national fare structure. We hope that the consultation will help deliver a simpler and better fare structure for all rail users.”