Forth Replacement Crossing

Why was the Forth Replacement Crossing built?

The need for an alternative crossing became clear when problems were discovered in the main cables of the Forth Road Bridge.

This meant it couldn't guarantee the levels of service needed to support social and economic traffic on the important road transport corridor across the Forth estuary.

Repairs to the existing bridge would've taken up to nine years, causing significant disruption to traffic and affecting the economy of Scotland.

Difference the Forth Replacement Crossing has made

Economic and social

The crossing touched the lives of many during its development.

It created 1,200 job opportunities in the local area and enabled many sub-contracts and supply orders from Scottish companies.

The project created employment for more than 15,000 people from over 30 nationalities with up to 1,500 people onsite at one time - 44% of the workforce were from local areas, and 43% from elsewhere in Scotland.

An intelligent transport system (ITS) was introduced. This has delivered more reliable journey times and improved user safety.

This smooths traffic flows and improves safety by slowing vehicles approaching the back of the queue.

A purpose-built contact and education centre provided a focal point for community engagement and educational activities.

Sustainability

Sustainable construction was promoted throughout the scheme.

One example was the use of 1.5million tonnes of locally sourced spent oil shale, a secondary recycled product. 

The scheme reflects the Scottish government’s commitment that the Forth Replacement Crossing (FRC) project replaces, rather than increases, the roads available for general traffic to cross the Firth of Forth. 

It's not government policy to provide unlimited growth in vehicle traffic and to attempt to do so would be unsustainable. 

Future travel growth beyond the opening of the FRC will need to be satisfied by increased use of public transport.

The Forth Road Bridge is now a public transport corridor making the journey significantly better for pedestrians and cyclists crossing the Forth.

This reduces the volume of traffic crossing the bridges.

Environmental improvements

Planting of 400,000 new trees from the seeds of local trees, mammal fencing and crossings have been incorporated into the new roads.

A sustainable urban drainage system (SuDS) provides temporary storage for runoff from the roads.

Noise air and light pollution were reduced using a low-noise road surface and noise screening structures.

The ITS is designed to reduce traffic emissions due to the smoother flow of traffic.

The installed lighting allows for dimming and remote control for future energy reduction.

New cycleways, footpaths and safe crossing points encourage active travel in the area.

How was the Forth Replacement Crossing built?

The replacement bridge is more reliable and more resistant to climate and decay than the Forth Road Bridge, as it's modern design uses the latest techniques and technology. 

Key features which enhance reliability include:

• Using the latest, most durable materials
• The cables can be replaced as part of normal maintenance works without closing the bridge as was the case with the existing road
• A dehumidification system inside the box girder reduces moisture, preventing corrosion
• Modern paint systems on the structure
• Use of thicker road surfacing with longer surface life which can be machine laid, making it easier to replace

The bridge deck carries two general lanes of traffic in each direction alongside hard shoulders to ensure that breakdowns and maintenance work don't cause severe traffic jams. 

This design also accommodates buses that get displaced from the Forth Road Bridge during dangerous weather conditions.

The innovative bridge design, incorporating a zone of “crossed cables” at mid-span provides extra strength and stiffness, allowing the towers to be slender and elegant.

The bridge’s has windshields, which means that traffic is now unaffected by high winds that have in the past closed the Forth Road Bridge (FRB) to high-sided vehicles.

Closing the bridge has a huge impact on the region’s economy, and recent closures of the FRB were estimated to cost the local economy £50m.

Car travel is now possible in winds up to 100mph as opposed to the 80mph wind restriction which existed on the FRB.