M4 relief road: How much public transport could £114m buy?

How many new trains or buses would £114m buy? How many public hire bikes could you install?

Why ask? Well, after the Welsh government announced it was scrapping plans for an M4 relief road, people might just want to know what the £114m spent on inquiries and developing plans in the years running up to this decision could have bought instead.

BBC Wales has taken a (very approximate) look at what we could have got for our money instead...

Let's start with trains. You may have noticed that Wales' trains look a bit different now after Transport for Wales took over running them last year.

While it's mostly branding that has changed for now, the new franchise is promising new trains by 2023.

It is spending £800m on 148 new trains. So using that measure £114m would have bought 21 of those particular brand new trains with a little bit spare for polish.

According to Roger Ford, technical editor at Modern Railways, the cash would buy a grand total of 26 four-carriage electric commuter trains.

If you follow a normal operating practice of leasing trains - including cleaning costs, maintenance and the works - Welsh commuters could have benefitted from 52 four-carriage trains for a whopping 10 years.

But we don't all live near a railway line. What about those all-essential bus services, which have been cut at a rate of knots as austerity bites into council subsidies?

Using Department of Transport costs of running a bus per mile from 2017-18, the money could have paid for 35 million miles of journeys. That's the same as 2.4 million journeys between Cardiff and Newport or 1.59 million trips from Colwyn Bay to Bangor.

Or, if you want it in terms of putting more buses on the roads, with an approximate cost of buying a standard single-decker at £165,000 - according to Arriva Buses - Wales could have an extra 690 buses on the road - up almost a third on current figures of 2,458 bus and coaches run by local operators.

If we wanted to boost our green transport credentials, making that fleet 100% electric would bring the number down to 350 (although installing the necessary charging infrastructure might eat into that budget quite significantly!)

With the obesity crisis growing, maybe the money would be better spent on active travel?

Bike hire schemes such as nextbike in Cardiff and Santander in Swansea could be expanded and extended to other towns.

nextbike estimate the £114m could purchase - including docking stations, infrastructure and staffing for a year - a "mammouth" 39,500 bikes.

Alternatively, the annual cost of membership for both schemes is £60. The money could cover that cost for 1.9 million Welsh people - very nearly the entire working age population, according to the Office for National Statistics.

Given we are a hilly nation, people might need a little help. Taking an average cost of an electric bike as £1,000, the government could provide a fleet of 114,000 e-bikes at strategic points around the country. Maybe not Snowdon...

And while we're on the subject of electric assistance, what about introducing an e-scooter rental scheme?

Having personally discovered the joys of nipping about on a scooter in Paris, your correspondent would be very keen to see this introduced in the admittedly wetter and colder climes of Wales.

Costs start at £80 per scooter, ranging up to about £2,000 for more high-end models. Because it's basically illegal to ride anywhere except on private land, there are currently no hire schemes in the UK to compare costs with.

Failing all that? Well, allowing a fairly modest £36 per pair, every person in Wales from a newborn to a centenarian could be gifted a pair of trainers.

Welcome to a greener, healthier (possibly slower) future!