Transportation services for the US Embassy in London

URS provided transportation planning support for the US Embassy, backing a planning application submitted by the US Department of State.

The proposals incorporated works and measures to enhance access and security arrangements at the prestigious London Embassy situated in Grosvenor Square. The measures included new vehicular and pedestrian security measures on all four sides of the existing building perimeter to replace makeshift features that were installed in the wake of the September 11, 2001 terrorist attacks on the US. The objective was to build permanent security measures that were both in harmony with the existing building and its urban surroundings, whilst making positive contributions to the security of the surrounding neighbourhood and to the overall character of Grosvenor Square.

A major challenge, yet fundamental to the overall success of the security regime, was the potential closure to general vehicular traffic of both Upper Grosvenor Street and Upper Brook Street at times of enhanced threat. Strategically placed rising bollards would limit access along both roads to only local residents and those on Embassy business. Both these roads provide major traffic conduits through the heart of Mayfair and as a consequence it was essential for URS to devise and promote acceptable traffic arrangements to manage the situation carefully and minimise the impact of traffic diversions on the surrounding network.

To satisfy the requirements of both Westminster City Council and Transport for London (TfL), the Transportation Assessment determined the impacts associated with:

• Access, servicing and parking;
• Local bus, tourist bus and coach operations;
• Pedestrians and cyclists; and
• The potential wider traffic diversion effects onto roads such as Park Lane, Park Street, Mount Street, South Street and at key junctions.
  
  

Network operations and solutions were evaluated using a variety of modelling applications to include LINSIG, TRANSYT and micro-simulation using VISSIM. This demonstrated the operation and impact of the planned diversion routing arrangements to satisfy the requirements of the planning authorities. These requirements included an extensive VISSIM model covering a network bounded by Oxford Street, Park Lane, Piccadilly and New Bond Street. The model was calibrated to the satisfaction of TfL’s network and traffic management team, with the scheme subsequently extended and eventually provided to TfL as an enhancement to its own VISSIM model of the Westminster area.

The modelling and scheme design required URS to devise and manage a complex area-wide traffic data collection exercise to include registration plate matching to determine origins and destinations, automatic traffic counts and parking surveys to provide accurate base data to inform the process and guide subsequent network modifications.

A critical part of the overall process involved close liaison with a range of representative bodies and organisations to include local residents’ groups and businesses, bus operators, TfL (Public Carriage Office, Street Management), The Diplomatic Protection Group, Metropolitan Police and the City Council.

Planning permission was granted in Autumn 2005. To follow the grant of permission URS was subsequently involved in providing additional support to the Embassy advising its legal team on highway matters during negotiations on Stopping-Up areas of public highway and in support of agreements under the Town and Country Planning Act (Section 106) and Highways Act (Section 278).