Transport and emissions modelling for the Sheffield & Rotherham Clean Air Plan (incudes Sheffield Clean Air Zone). Direct contract award to SYSTRA Ltd via the ESPO Business Consultancy framework 664_25 LOT 5 Highways, Traffic and Transport. Approved by Authorised Officer.Transport and emissions modelling for the Sheffield & Rotherham Clean Air Plan (incudes Sheffield Clean Air Zone). Direct contract award to SYSTRA Ltd via the ESPO Business Consultancy framework 664_25 LOT 5 Highways, Traffic and Transport. Approved by Authorised Officer.