Superfast broadband is now available to almost three-quarters of UK homes, and the number using it has more than doubled in a year.
Public Wi-Fi hotspots are also being more widely used, with the number doubling over the year to 34,000, according to the regulator’s annual Infrastructure Report.
But Ofcom's first analysis of 2G and 3G coverage on the UK's roads estimates that just 35 per cent of the length of A and B roads are served by all four 3G networks, and 9 per cent has no 3G coverage.
It said the shortfall should partly disappear with the roll-out of 4G services, but confirmed that it would carry out more studies over the next year "to examine whether regulatory or Government intervention may also be required to achieve wider mobile coverage on roads".
Ofcom will also examine mobile coverage on major rail routes over the coming year and advise the Department for Transport and Network Rail on how to make improvements.
Ofcom chief executive Ed Richards said: "Superfast broadband is rolling out fast across the country, and 4G mobile will reach at least 98 per cent of the population. This is really good news but there remain considerable challenges, not least in hard-to-reach areas for mobile and home Internet services.
"We know consumers increasingly expect superfast speeds, but it's also important to make sure people can connect over a very wide area. That is why we are doing everything we can to support moves to improve coverage in difficult areas such as roads and train lines."
The report said that in June 73 per cent of UK premises could receive superfast broadband, up from 65 per cent in 2012, and 22 per cent of broadband connections were superfast, up from 10 per cent last year.
The regulator said the trends reflect wider changes in the UK's communications infrastructure, which it said was evolving to meet consumers' growing demand for data at home and on the move.
Around 4.8 million UK customers have taken up the technology, up from 2.1 million last year.
In total, 650 million gigabytes of data were sent or received by UK Internet users over fixed lines in June, an increase of 26 per cent over the same month last year – an amount of data equivalent to more than a billion copies of the Encyclopaedia Britannica.
Culture Secretary Maria Miller said: "This report is further evidence of the amazing transformation that broadband in Britain is currently undergoing.
"Both coverage and take-up are steadily increasing, and more than 10,000 rural homes and businesses are now gaining access to superfast speeds every week as a result of the Government's nationwide roll-out."