The modernization of the U4 underground line will increase reliability for passengers only to a limited extent

The modernization works along the Vienna U4 underground line will boost reliability for passengers only to a limited extent. This was pointed out by the auditors of the Austrian Court of Audit (ACA) in their report published today on Vienna’s public transport operator Wiener Linien “Wiener Linien – Modernization of the U4 Underground Line”.

In addition to the potential to increase reliability, the ACA assessed the Wiener Linien’s performance of tasks in its capacity as the builder-owner, the development of costs and schedules and the entire construction process starting from the awarding of contracts to the settlement of costs. The audit spanned the years from 2014 through 2018.

In 2011 and 2012, the U4 underground line experienced an increased number of service disruptions. At that time the Wiener Linien stated that the overall punctuality of the line had deteriorated, among others, due to the high age of the underground system. In 2012, the Wiener Linien were commissioned by the then responsible city councillor to assess a “large-scale” modernization of the U4 underground line. The main goal was to increase the reliability (“constancy of intervals”) and the operational safety. 

Reliability: the passengers’ perspective

According to the viewpoint of the passengers, the reliability of the U4 line was basically below the average of all underground lines in the period of 2009 to 2018. Also as regards the number of infrastructure-related disruptions, the U4 line was often above average in the period of October 2013 to December 2018. It should be noted that the reliability of the U4 line was nevertheless at a high level, namely between 99.65 per cent and 99.95 per cent. An unusually long disruption of the U4 occurred on 25 October 2019. According to the Wiener Linien, this resulted from a malfunction of a now 40-year-old relay interlocking. 

Reasons for downtime

Overall, 51 per cent of the cases of downtime on the U4 line were attributable to the subway cars, 30 per cent to customers and/or external factors and 14 per cent  to the infrastructure. The figures concern the years 2009 to 2018. The modernization of the infrastructure will therefore contribute to increasing the reliability of the U4 line only to a limited extent. The ACA recommends to the Wiener Linien to communicate this to the public.

Until the end of the project in 2024, about EUR 379 million are to be invested in the modernization of the U4 line. Only 15 per cent of these forecast costs concern measures that are directly perceivable by the passengers, such as the renovation and the renewal of stations, platforms, escalators and staircases as well as the installation of video surveillance. 

Analyse the number and duration of disruptions

The ACA recommends to the Wiener Linien to proactively communicate their efforts to increase the reliability and operational safety of the U4 line based on understandable parameters. The public relations work should not be limited to the reliability parameter. Other parameters that are tangible for passengers, such as the number and duration of disruptions, should also be published. Since February 2017, Wiener Linien has had corresponding tools for such an evaluation.

The Wiener Linien as a proactive builder-owner 

The ACA came to the conclusion that the Wiener Linien assumed its function as builder-owner in a proactive manner. Furthermore, the Wiener Linien had appropriate regulations in place as regards governance and the modus operandi, even though they had some shortcomings. The project management was, in general, suitable. However, the ACA criticized that the risks had not been consistently assessed. Neither did the Wiener Linien undertake a valorisation of the costs incurred until the planned end of the project in 2024 until July 2017.

Cost increase at the Stadtpark station 

Among others, the ACA took a closer look at the Stadtpark subproject. Initially, a contract had been awarded with regard to master builder and expansion works amounting to EUR 1.80 million. However, the order amount increased by 23 per cent – the final account was at EUR 2.15 million. This increase was attributed to additional works. However, of the 381 agreed services tendered, only 242 were carried out and charged. As regards the subproject related to the Stadtpark station, the ACA critically points to the increase in costs and the considerable amount of additional orders of about EUR 422,000. The service specifications were deficient and of insufficient quality. Thus, the Wiener Linien furthermore created potential for speculations for the bidders. 

The ACA has pooled and published its knowledge from 55 ACA audits of construction projects in its "Construction Guideline" (available in German), which offers guidance for the transparent, traceable and legally compliant management of public construction projects. This guideline, which was published as early as in 2018, is to contribute to the economic, efficient and effective management of construction projects for the benefit of citizens. 

Furthermore, the ACA published its report "Internal Control System Regarding the Debt and Investment Management of the City of Vienna" (in German).