Since construction of the Jubilee Line Extension first began in December 1993, the same question has asked over and over again by the public, politicians and journalists alike - when will it be open?
At the start of next month the question will cease; trains will run from Stanmore to Stratford non-stop. By the end of the year all stations will be open and operational. The JLE will morph into the Extended Jubilee Line.
But is it really possible to describe a project which finishes 20 months late and £1.4bn over budget a success?
Yes, is the answer. We cannot ignore the reality that the project has not always gone smoothly and that there were many mistakes made and hard lessons learnt, but a success it is never-the-less.
Six years' work and £3.3bn has delivered a significant piece of infrastructure which sets new standards in everything achieved. Stations are bigger and grander than anything before it. The complexity of construction has pushed back the boundaries of what is possible. The standard of architectural detail and public information systems inside them is a revelation. In between the ride quality is smoother than anywhere else on the Tube network.
And there is more to come. Westminster Station will complete the line up of stations truly fit for a 21st Century transport system - the first step toward London Underground's goal to create a 'decently modern metro'.
While a few people will be singled out for credit in delivering this mammoth project, it is important to remember that thousands more have been involved in the job. Though the glass and stainless steel finishes will grab the limelight, it will not obscure the unprecedented achievements of the heavy construction teams, who long ago successfully carved this work of art beneath central London.
Most heartening is that throughout the project's many ups and downs, safety has remained at the highest priority. There have been accidents but no single worker has been killed during the entire construction period. Alongside the construction industry norm this is an outstanding feat.
This is New Civil Engineer's third supplement on the JLE project. Certainly the project has finished late and over budget, but opening of the line brings much to celebrate. Be proud, go and ride the new line and see the stations for yourself - JLE is a massive construction achievement.
Antony Oliver New Civil Engineer