Building a Highway

The Transportation and Infrastructure department’s planning and land management branch take special care in choosing what they call a highway “corridor,” a width of land suitable for placing a highway.

They must make sure the new corridor is a balance of engineering, environmental, social and economic concerns.

To do this, they develop a detailed map and compile and analyse a lot of information on geographic, traffic, and environmental constraints as well as existing development.

The department then hosts public meetings so that New Brunswickers affected by the highway can see the proposed corridor and make comments. Changes are often made due to input received at these public meetings and are sometimes taken back to the public for further input.
   

The new corridor is registered with the Department of Environment and Local Government and the provincial environmental impact assessment process begins. Preliminary field surveys and environmental studies take place. The centre line of the highway is also surveyed. Designers use this information to create preliminary designs and identify how much land is needed. Environmental consultants use the centre line to help them identify where sensitive areas might be. Environmentally sensitive areas may include areas of rare plants, endangered species, wetlands, deer/moose yards (wintering areas frequented by deer/moose), etc. Based on these studies, environmental conditions are placed on the design, construction and maintenance of the highway and these must be incorporated in the work.

A federal environmental process under the Canada Environmental Assessment Act may also apply.
   

The department’s design branch uses the functional plans to carry out a detailed survey and design. Project specifications are developed.

The department designs the highway using Transportation Association of Canada guidelines and accepted safety standards to maximize the protection of the travelling public.

Right of Way agents negotiate with land owners to purchase the land needed for the highway.
   

Once the land has been acquired and a contractor retained through a public process, construction work begins at the site of the new highway.

Construction signs are installed to warn motorists of the work. Any utilities that may be affected are removed and/or relocated. Environmental measures such as silt fences and erosion control structures are installed around any watercourses.

The area where the road is to be built is cleared of trees. All merchantable trees are salvaged. After the trees have been removed, the remaining stumps are removed by equipment with root rakes, which do not remove the valuable topsoil.

The area where the road is to be built is cleared of trees. All merchantable trees are salvaged. After the trees have been removed, the remaining stumps are removed by equipment with root rakes, which do not remove the valuable topsoil.

Most roads are designed to maximize the material available on site. This is called common excavation or solid rock excavation. Excavated material is moved by large equipment such as bulldozers, excavators, and trucks. However, sometimes some material needs to be imported to the site. This material is called “borrow”.

As the highway is constructed, layers of soil, rock and crushed rock are compacted by equipment to make the road strong. As work continues, exposed areas are stabilized by planting grass. Areas that are prone to erosion are protected by rock called riprap.

The final touches to the grading portion of the road are to topsoil the slopes and plant grass using hydroseed. Now that this is complete, the road is ready to be paved with asphalt.
   

Structures are used to carry traffic over other roads, railway tracks, or water. Structures are also called overpasses, underpasses, or bridges.

Structures can be single span or multi-span with columns between each span. A structure consists of footings, piers, piercaps, abutments, beams and a deck.

The footing is the base of the structure. The pier sits on top of the footing and supports the piercap. The piercap supports the beams and the beams in turn support the deck. The abutments form the start and end of the structure and support the beams as well.

The first step in building a structure is to build a strong footing. Generally the structure is founded on firm ground. If the ground is not firm enough, then piles are driven to provide the necessary support. Once this is done, the shape of the footing is determined using a “form” and concrete is poured into the form. Once the footing is hard enough, piers are “formed” on top, followed by the piercap. The abutments are then completed. Once all of this work is complete, beams are placed. Beams can be either concrete or steel. Once the beams are placed, then the deck is placed. A protective barrier wall is installed and the deck is waterproofed to prevent water from seeping into the concrete. The final touches are to pave the deck with asphalt and mark the road.
   

The New Brunswick Department of Transportation and Infrastructure uses asphalt to pave the highway. Asphalt is a mixture of stone, sand and asphalt cement, which gives the asphalt its black look and binds everything together. The asphalt is placed and compacted to provide a smooth and dense surface for traffic to drive on. It is sloped so that the water rolls off the highway.

When the asphalt has been placed, the guide rail is installed, electrical wiring is run to provide power to the lights, signs are installed and the marking on the road are painted. The road is now ready to be opened.