The A9 Dualling scheme is a £3 billion road improvement programme to upgrade 80 miles of the A9 to dual carriageway.  Sine Environmental supported Jacobs U.K. Limited by overseeing the noise modelling and drafting the noise chapters of the Stage 2 Scheme Assessment Reports for five sections of this scheme (from the Pass of Birnam to Glen Garry, with a total length of around 48 km). This stage focused on ascertaining the difference between proposed route options for each section, by calculating noise levels for each option and then classifying the change in noise levels in accordance with guidance from the Design Manual for Roads and Bridges (HD 213/11). The project included working closely with other members of the joint venture, including the CH2M Hill UK acoustics team (previously led by Sam Williams, a Director of Sine Environmental) and Atkins, to develop a standard noise methodology adopted by all three teams for the assessments across all of the contract areas.