Time wasted in the worst traffic jams in Edinburgh and Glasgow will cost drivers more than £5bn by 2025, according to a new study.

Transport information company Inrix identified more than 20,000 congestion pinch points in 21 cities across the UK.

London had the worst hotspot on the M25, while Edinburgh's westbound A720 city bypass, at the Dreghorn junction, was the second worst.

The third worst in the UK was the eastbound junction of the A8 and M8 in Glasgow.

The report said the London hotspot on M25 northbound between junctions 15 and 16, near Heathrow Airport, would cost drivers £42bn by 2025.

Edinburgh was in second place at £2.8bn, followed by Glasgow (£2.3bn), Birmingham (£2bn) and Manchester (£1.9bn).

Inrix estimated that the total cost of traffic jam hotspots in the UK would be £62bn, based on hours wasted in queues.

It was based on analysis of the average duration, length and frequency of traffic hold-ups in September.

The figure was calculated using value of travel time figures from a Department for Transport-commissioned report.

This was more than any other country in Europe, with Germany the next closest at £42bn and Italy third at £19bn.

In last week's Autumn Statement, the Government pledged to spend £220m to tackle congestion on England's motorways and major A roads.

Inrix's chief economist Graham Cookson said identifying where delays are having the biggest impact can allow for the most efficient use of investment.

He said: "Let's make sure we focus spending on those worst-hit hotspots because, given the amount of money, we want to get the most benefit out of it."

A Transport Scotland spokesman said: "We are taking a range of actions to tackle congestion, working with partners in local government and across transport sectors.

"We are currently seeing a massive investment programme with £8 billion being ploughed into our motorways and trunk roads since 2007, including the M8, M73 and M74 improvements which will cut 20 minutes off the journey time between Glasgow and Edinburgh during peak times.

"The amount of traffic on the A720/M8 has increased greatly in recent years and we are investing £200k at the Hermiston Gate roundabout to improve the flow of vehicles and next week are publishing a range of options to tackle congestion on the A720 at Sheriffhall roundabout.

"On a more strategic level, we are reviewing our Intelligent Transport Strategy to establish how we can make journey times more reliable, supporting the economy in the process.

"We are committed to a review of the National Transport Strategy within the current parliament to establish what transport in Scotland should look like in the coming years and this will inform our second Strategic Transport Projects Review.

"Work is also continuing to encourage people to consider alternative modes of transport and the Scottish Government is investing over £1bn per year in public and sustainable transport.

"We very much appreciate the patience of drivers and we give them as much real time information as possible through the Traffic Scotland service to allow them to plan their journeys to avoid congestion hotspots where possible."