R&I spotlight: benchmarking Metro and Light Rail construction costs

This Research & Innovation project set out to compare the construction costs of Metro and Light Rail systems.

We assembled cost data for forty systems worldwide, twenty of each type. The comparison was based on estimates of the construction cost per kilometre of line.

It showed, not surprisingly, that costs for Metro were higher than for Light Rail, but also that the picture is more complicated than that.

There are wide cost variations within each type of system, and these seem to be due to factors such as:

• City densities, which can affect the costs of delivery of materials and construction activity.
• The features of the line, especially how much of it is below ground, at surface level, or elevated.
• Local economic and social factors such as the availability and cost of skilled labor.
• The ratio of Metro to Light Rail unit costs also varied by region and, at the time of the project completion, it was around 6 for Europe, Africa and Asia, but 1.6 for North and South America.

A regression model was built relating unit costs to the factors found to generate differences in costs. This explained about 50% of the variation in costs.

The results were used to build a spreadsheet capable of providing initial estimates of Metro and Light Rail unit construction costs, given a base specification.

Key value of the project

• A substantial database of Metro & LRT construction costs from projects across the world
• Insights into what causes these costs to vary
• A model for providing initial estimates of construction costs to a given specification

About our R&I Program

Our Research and Innovation (R&I) Club, which recently celebrated its 100th Meeting, epitomizes the insightful research and continuous innovation culture of Steer Davies Gleave. Since its formation in 2013, the club regularly brings together staff of all grades, disciplines and offices to work collaborative – and has successfully completed over 80 projects.