Bus Emissions Test Cycle Development

At a glance

Millbrook has over 25 years of experience in generating bus test cycles to aid the development and certification of emissions, range, and energy and fuel consumption.

Bus test at Millbrook Proving Ground
Bus emissions test cycle engineers working in the VTEC at Millbrook Proving Ground

Millbrook London Transport Bus Cycle (MLTB)

Millbrook developed the iconic Millbrook London Transport Bus (MLTB) cycle in 1996. The cycle was run within the controlled environment of Millbrook’s Variable Temperature Emissions Chamber (VTEC), to achieve repeatable results.

Bus test at Millbrook Proving Ground

Transport for London (TfL) used the MLTB bus emissions test cycle to check that new buses met their required low emissions and fuel economy standards. It has also been used in development of retrofit after-treatment bus emissions systems used on older vehicles.

Over the years, the cycle has been rebaselined against real world emissions data and has been found still to be applicable for representing an inner and outer London bus operation.

UK Bus Cycle

The MLTB bus emissions test cycle used by TfL and the national Ultra Low Emission Bus (ULEB) accreditation scheme have been unified into a procedure that fits the wider UK market.

The Low Carbon Vehicle Partnership (LowCVP), supported by Millbrook, developed the UK Bus Cycle (UKBC). The procedure is used to approve vehicles for incentive schemes such as the green bus fund and CVRAS. It challenges the industry to develop cleaner and more fuel and energy efficient vehicles. Bus manufactures and system suppliers use Millbrook’s VTEC to develop their products prior to Millbrook performing the required approval testing.

See VTEC specification

Bus emissions test engineer working in the VTEC at Millbrook Proving Ground

Custom Bus Emissions Test Cycles

Millbrook has developed on-track bus emissions test cycles for various bus operators with the aim of improving bus and fleet fuel economy. Millbrook uses the wide range of its UK test tracks at Millbrook Proving Ground to form a duty cycle covering real-world use of the vehicle by its operator. Buses are then tested in a controlled and repeatable way to develop their fuel economy and perform validation testing.

Millbrook has used its knowledge of bus operations and European Emissions Regulations to develop Real Driving Emissions (RDE) compliant bus routes on the public highway on which it uses its Portable Emissions Measurement Systems (PEMS) to measure the regulated emissions, CO2 and fuel economy. Millbrook has been approved by the Vehicle Certification Agency (VCA) to perform EU RDE certification and in-service compliance testing.