Rehabilitation of Trunk Road 31 from Ashton to Montagu including the New Ashton Arch Bridge


Filter projects by:


  • Cities

    Cities EMIA

  • Civil Works

  • Commercial & Residential

    Mixed Use




  • Dams & Hydropower

  • Disaster Resilience

  • Education

    Colleges & Universities


  • Energy

    Carbon capture, utilization and storage


    Grid modernization



    Microgrids and energy storage

    Offshore wind

    Portfolio Decarbonization and Climate Resilience


    Transportation decarbonization

  • Environment

  • Flood and coastal resilience

  • Healthcare

    Clinical Hospital

    Life Sciences

    Senior Living

  • Industrial

    Agriculture, Food & Beverage

    Automotive & Heavy Equipment & Machinery

    Digital Infrastructure

    High Performance Logistics


    Mining & Metals

    Pharmaceutical/Specialty Chemicals

    Pulp & Paper

  • Industrial Water

  • Infrastructure & Facilities

  • Justice

  • Leisure

    Arts and Culture

    Hotels and Resorts

    Themed Entertainment and Mixed-Use

  • National Governments

  • Oil, Gas & Chemicals





  • Sports and Venues


    Convention Centers

    Olympics & Mega-Events

    Stadiums & Arenas

  • Transportation

    Air Cargo


    Bridges & Tunnels

    Connected and Autonomous Vehicles

    Freight Rail

    Highways & Roads

    Mass Transit

    Ports & Marine

    Transportation decarbonization

  • Tunnels, Conveyance, Collection & Distribution

  • Wastewater Treatment & Reuse

  • Water

  • Water Treatment

  • Watershed and Ecosystem Management


  • AECOM Capital

  • Alternative Delivery Models

  • Architecture and Design


    Asset Advisory

    Interior Architecture

    Urbanism + Planning

  • Asset Management

  • Cities Solutions

  • Construction Management

  • Converged Resilience

  • Cost Management

  • Digital Infrastructure Services

  • Economics

  • Electric Vertical Takeoff and Landing Solutions

  • Engineering

    Ground Engineering

  • Environmental Services

    Air Quality Consulting and Engineering

    Climate Adaptation

    EHS Management Consulting and Compliance

    Environmental Contracting

    Environmental/Social Impact Assessment and Permitting

    Management Information Systems (MIS)

    Remediation, Restoration and Redevelopment

  • Fabrication

  • Finance

  • IT and Cybersecurity

  • Mobilitics

  • Multinational Investment and Development

  • Pedestrian Modelling (North America)

  • Planning and Consulting

    Geospatial Services

    Pedestrian Modelling

  • Process Development & Implementation

  • Program Management

  • Public-Private Partnerships

  • Risk Management & Resilience

    Critical Infrastructure Protection

  • Simulation Models

    Rail Simulations

  • Strategic consulting

    People + Place Advisory

  • Tunnels, Trenchless Technology and Underground Infrastructure

  • Vertical Transportation Services (North America)

  • Visualization and Virtual Reality


  • Africa

  • Algeria

  • Antarctica

  • Australia

  • Azerbaijan

  • Bahrain

  • Bangladesh

  • Belgium

  • Bolivia

  • Bosnia and Herzegovina

  • Brazil

  • British West Indies

  • Canada

  • Caribbean-Puerto Rico

  • China

  • Colombia

  • Croatia

  • Czech Republic

  • Egypt

  • Eritrea

  • Finland

  • France

  • Germany

  • Greece

  • Greenland

  • Haiti

  • Hong Kong

  • India

  • Indonesia

  • Iraq

  • Ireland

  • Italy

  • Japan

  • Kenya

  • Kingdom of Saudi Arabia

  • Kuwait

  • Liberia

  • Lithuania

  • Malaysia

  • Maldives

  • Mali

  • Malta

  • Mauritania

  • Mexico

  • Monaco

  • Mongolia

  • Montenegro

  • Myanmar

  • Netherlands

  • New Zealand | Aotearoa

  • Norway

  • Oman

  • Panama

  • Papua New Guinea

  • Peru

  • Philippines

  • Poland

  • Portugal

  • Qatar

  • Romania

  • Singapore

  • Slovakia

  • South Africa

  • South Korea

  • Spain

  • Sri Lanka

  • Sweden

  • Switzerland

  • Taiwan

  • Turkey

  • Ukraine

  • United Arab Emirates

  • United Kingdom

  • United States

  • Vietnam

  • Worldwide

The Western Cape Department of Transport and Public Works identified two sections of Trunk Road 31, totaling a 13.4-kilometers, between the towns of Ashton and Montague for rehabilitation. This was needed to improve traffic and pedestrian safety, as well as enhance the flood capacity of bridges along the route.

The road is also the start of the strategically important tourist Route 62, on which 4,000 vehicles travel through Cogmanskloof Pass towards Montagu everyday.

The upgrade of Cogmanskloof Pass presented several challenges due to significant ecological and heritage constraints, and extensive rock cutting required to realign the narrow gorges. These were overcome through considerate design and landscaping, and the preservation and reinstatement of indigenous vegetation.

The Cogmanskloof River flows adjacent to much of the route and crosses the road at four locations by means of existing bridge structures, which did not have adequate hydraulic capacity. The greater Ashton-Montagu region, and Cogmanskloof Pass in particular, had experienced substantial flood damage that resulted in multiple road closures and significant operational disruptions, with adverse impact on the local economy.

Three new bridges crossing the Cogmanskloof River were constructed during the project, the most iconic of which is the New Ashton Arch Bridge, which had been repeatedly damaged by floods and no longer fulfilled its functional purpose. Sediment build-up had significantly reduced the bridge’s freeboard height. During flooding it became clogged with debris and was overtopped by the river, cutting off the town.

To replace Ashton Bridge, we designed a single span, 100-meter, concrete tied-arch solution with a suspended deck. It accommodates four traffic lanes and walkways for pedestrians. To minimize traffic disruption, the new structure was constructed adjacent to the pre-existing bridge. After completion the new bridge was used as temporary bypass while the existing bridge was demolished, and new abutments built. The new concrete tied arch bridge was then jacked transversely into its final position in less than 12 hours. This was the first application of this bridge engineering technique for a concrete tied-arch bridge in South Africa.

Local manufacturers, with support from overseas specialists, were used to manufacture and supply specialized components such as post tensioning systems, arch stay cables, anchor plates and support bearings. On completion of the project, 42 per cent of the contract value had been allocated to the creation of economic opportunities and entrepreneurial capacity in the surrounding areas over five years.