Where highways & bridges cross over roads, railways & water courses overpass & bridge structures are constructed. The type of construction depends on the required spans & the presence of active traffic below.



For relatively short span lengths that cross over active traffic then precast concrete girders are normally the most cost effective solution. Longer spans would require switching to steel girders. If the structures can be built in open areas with no traffic or require longer curved spans, then cast in place post-tensioned structures are an option.

River Crossings normally include approach structures on land joining into a main long span river bridge. The approach spans are normally constructed like overpasses & vary from precast girders, steel girders or cast in place segmental construction. The river bridge can also be constructed with girders if the option to construct the piers in the river utilizing berms, cofferdams or trestles is possible. This option may not be allowable due to river depth, environmental concerns or navigation requirements. In these cases, much longer span solutions are required like cast in place segmental & cable stay structures.

The overall quantity of the bridge assembly is the deck or supported area. The costs at the top level of the breakdown are shown as a unit cost per deck area. When importing a complete structure, you can create a feasibility estimate by simply updating the resource rates & prorating the deck area.

Refer to HCI-420-Cast in Place Concrete

Refer to HCI-430-Highway Overpass Structures

Refer to HCI-450-River Bridge & Approach Structures

The availability of granular sources close to a highway project is crucial to keeping the costs down. If existing commercial sources are not available close to the project a contractor may have to open their own quarry or borrow area. Permitting for granular sources is not an easy process. Contractors who control their own granular pits are often the most competitive.

Refer to HCI-510-Process Aggregates

Refer to HCI-520-Paving & Site Improvements

Refer to HCI-530-Roadway Configurations

Pavement structures are normally classed as Flexible Pavement or Rigid Pavement. Flexible Pavement consists of thick layers of granular base with several layers of asphalt. Rigid Pavement consists of a thin layer of drainage granular covered by a thick layer of concrete pavement. The selection of the best most cost-effective solution over time depends on the climate, subgrade condition & the relative cost of asphalt cement vs portland cement. Asphalt is often the cheapest short-term solution but may have a shorter life span requiring more future maintenance & rehabilitation.

Refer to HCI-520-Paving & Site Improvements

Refer to HCI-530-Roadway Configurations

The final improvements for a highway project depend on its location, safety requirements & noise abatement requirements. For restricted rights of way, concrete barriers & guiderail systems are required. If the highway is close to residential areas, then tall soundwalls are required. Metropolitan highways require extensive overhead directional signage.

Refer to HCI-520-Paving & Site Improvements

The standard of lighting varies depending on the location of the highway, whether in Metropolitan areas or in remote isolated areas. Again, depending on location lighting can include highmast light poles, regular poles, underground conduit, cabling & electrical substations.

Refer to HCI-720-Roadway Lighting & Signals

This is normally the final phase of the project & consists of predominately hydroseeding & limited planting.

Refer to HCI-520-Paving & Site Improvements

Depending on the length & location of the project the workforce may have to live in temporary accommodations. These are usually covered by paying live out allowances and & mileage.

Refer to HCI-940 Regional Project Indirect Assemblies

On a highway project, particularly with extensive excavation & grading the schedule is susceptible to bad weather particularly rain & frost. Its common for contractors to work extended hours to take advantage of when the weather is good.

Refer to HCI-010-Labor Rates for development of Overtime Rules

Highway projects are normally constructed by local or regional contractors. Large river bridges may attract larger construction joint ventures.

Refer to HCI-940-Regional Project Indirect Assemblies