PLANS to spend £300 million modernising the Glasgow Subway should be "rationally reassessed", and authorities should consider closing under-used stations and even a complete shutdown of the network, one of the UK's leading urban transport experts has claimed.

Peter White, professor of public transport systems at the University of Westminster, told the Sunday Herald that there is a case for a "rational reassessment" of the 117-year old network, and that a "fundamental reappraisal" of such a "low-usage" system is a "sensible thing to do."

The world's third-oldest fully underground segregated rail network, the subway is now one of the least used, its approximately 13 million annual users placing it at 135th out of 150 global urban rail networks. Tyne and Wear Metro, the UK's next best-used system (ranked 115th) carries 37 million, while the much larger London Underground, the world's 10th busiest, carries 1.2 billion each year.

White said: "Ridership is fairly modest. The changed pattern of land use has affected it. Various options could be examined as well as an all-or-nothing approach."

Complete closure of the system, he said, "could be considered in principle". He added: "While very heavily used in general, London Underground has closed some minor stations in the past, and closed the Holborn-Aldwych section of the Piccadilly Line about 20 years ago."

White was responding to a detailed critique of the economic case for Glasgow underground obtained by the Sunday Herald from a former long-serving senior executive of Strathclyde Partnership for Transport (SPT), the quango that runs the underground.

The ex-official, who has asked not to be named, claimed that "Glasgow politics" and the "nostalgia factor akin to that surrounding shipbuilding on the Clyde", rather than rigorous cost-benefit analysis, were behind the Scottish Government's decision to fund the upgrade programme announced last year.

As estimated increases in traffic did not justify the scale of spending on the upgrade, he wrote: "SPT should consider closing the network entirely."

He said: "The projected patronage following modernisation is 18 million trips by 2040. These are not massive numbers and, by comparison to the same system carrying 30 million-plus in the 1940s and 1950s, very unimpressive."

As well as the transformation of Glasgow's cityscape the source also pointed to the cost inefficiencies of a unique gauge system that makes obtaining spare parts for its bespoke mini-carriages "impractical, very expensive and unjustifiable".

He also noted that transport modelling reported in Transport Scotland's 2009 strategic transport projects review confirmed that, "gridlock and traffic pollution would not occur in Glasgow were the subway to close".

The document concluded: "If the city planned better integration of transport and land use by developing areas adjacent to the stations then the subway may possibly have a future role, however, given the likely pace of development in Glasgow over the next decade, the falling patronage and the predicted state of the economy, the option of closing the doors [of the underground] should be reconsidered."

The Scottish Government, led by Deputy First Minister Nicola Sturgeon, announced in March 2012 that it would provide £246m for the overall underground project, including new driverless trains and signalling.

This is about 85% of the total £296m project, which will not require the closure of the network.

It will be the third major revamp in the subway's history, after electrification in the 1930s and the 1977-1980 shutdown.

That latter project saw the subway almost entirely rebuilt, although the route and its access points continue to reflect the population dispersal, transport modes and travel patterns of the Glasgow of the 1890s.

SPT has claimed that its research into the modernisation of the system found that £150m could be saved over a 30-year period through a reduction in operation and maintenance costs and increased revenue by adopting a modernisation strategy.

"The modernisation will transform the system and result in increased patronage, which could potentially reach 18 million by 2040," the agency has claimed.

A spokesman for SPT said: "SPT's subway modernisation plans were subject to extensive analysis by highly-regarded transport consultancies – Transport Scotland and Scottish Government – and found to be robust.

"Stations with lower patronage numbers are, generally, in areas also considered to be in need of regeneration. Why would we shut those rather than working with partners to improve transport links and the area as a whole?"