Is Saudi Arabia about to draw a line through its landmark mega-project?

Saudi Arabia has called in consultants to review its landmark The Line project, with questions raised about the future of the untried infrastructural endeavour, amid a reported huge overrun in costs.

The experts will review The Line - a planned 170km linear city - to see whether its current blueprint is feasible and put forward possible alterations to the ambitious mega-project, according to Bloomberg.

The state-run Public Investment Fund (PIF) will have the final say on the recommendations and could still decide to run with The Line in its current form, which will be a centrepiece of the much-touted new city of NEOM.

"As is typical with large-scale, multi-year projects, strategic reviews are common practice and occur several times over the course of a major development project or infrastructure program," NEOM said in a statement, which is overseeing the project.

"The Line remains a strategic priority and Neom is focused on maintaining operational continuity, improving efficiencies and accelerating progress to match the overall vision and objectives of the project."

The Line was originally meant to be the most advanced city in the world, with no traffic, roads, or carbon emissions, and residents and businesses inhabiting a stretch of land 170km in length and 500m in height.

The proposed 9 million population - the same as London - would be shuttled across the city in not yet devised trains running 510-kilometre-per-hour.

They would be capable of reaching from one end of The Line to the other in just 20 minutes.

Yet there have been huge questions over the feasibility of a project relying on still-unimagined technology to power the city, but also the tremendous costs it would entail to build.

Oil is currently at $71 a barrel, while Bloomberg estimated that Crown Prince Mohammed bin Salman would need the price to run at around $113 to see his mega-projects come to fruition.

The de-facto ruler is looking to shift Saudi Arabia away from a reliance on oil and gas receipts to a more diversified economy, with a list of major infrastructure - costing an estimated $3 trillion - key to this transformation.

One suggestion has been a scaled-down version of The Line, with the city spanning just 2.4 km by 2030, with a population of 300,000 instead of the projected 1.5 million inhabitants. 

NEOM insists the project will still go ahead, but there could be a more realistic timeframe set for its completion.

Among other projects in Saudi Arabia's Vision 2030 is a floating industrial complex known as Oxagon, a luxury island resort called Sindalah, and the Trojena development for the 2029 Asian Winter Games.