Researchers from the University of the West of England (UWE) analysed rail passengers' use of free WiFi on Chiltern Railways-operated commuter routes between London and Birmingham and London and Aylesbury.
The survey of 5,000 passengers found that many used their journey to "catch up" with work before or after their working day.
Interviews with respondents also revealed that a large number used this buffer period to, for example move from being a parent getting children ready for school to their management role.
The researchers took inspiration from Norway where some commuters can count travel as part of their working day.
Dr Juliet Jain said: "If travel time were to count as work time, there would be many social and economic impacts, as well as implications for the rail industry. It may ease commuter pressure on peak hours and allow for more comfort and flexibility around working times. However, it may also demand more surveillance and accountability for productivity."
As part of the study, Chiltern Railways incrementally increased the quantity of complimentary WiFi available over 40 weeks in 2016 and 2017.
Results showed that on the Birmingham to London route, the proportion of commuters that connected to the free WiFi rose from 54% when offered 20MB a second to 60% when it was raised to 125MB a second. In comparison, connection by mobile data networks was around 48%.
The UWE team noted that, if employers were to consider commuters' journeys as part of the working day, train operators and telecoms industries would need to invest more money to improve working conditions, including tables, power sockets and continuous connectivity for internet and phone calls.