Construction of the new Camp Street Bridge is powering ahead, with piling now under way to build the foundation of the bridge across Lake Forbes.

Minister for Regional Transport and Roads Paul Toole said the $12.8 million project would deliver a stronger, wider and safer crossing.

"The first major milestone of the new Camp Street Bridge project has been achieved with piling starting (last Thursday); using a piling rig, drilling rig and a 50 tonne crane working from a temporary rock platform in the waterway," Mr Toole said.

"Eighteen large steel tubes will be inserted into the bedrock below the lake and will be filled with reinforced concrete to support the new bridge.

"The new bridge will be a win for the community and visitors alike, providing a safer and more efficient crossing over the lake."

Piling work will be carried out between 8am and 5pm on weekdays and is expected to be complete in four weeks, weather permitting.

The old Camp Street Bridge was built in 1927.

The final traffic crossed the old bridge on Sunday, August 25 and removal of the light posts that featured on the historic bridge and the pedestrian walkway added a few years ago were the first steps. Both will be reused.

In the weeks since, the decking of the old bridge has been cut into pieces and removed section by section while rock was placed underneath to create a working platform for the equipment.

The new 70-metre bridge will be 11 metres longer than the original bridge and will include wider lanes, wider shoulders, and pedestrian and cycle paths.

At the same height as the original bridge, it will be made up of 133 precast concrete planks placed in seven 10 metre spans.

The new bridge is expected to open to traffic and pedestrians by August 2020, weather permitting.

Alternative routes for light vehicles and school buses are available using local roads.

Heavy vehicles are detouring via Wirrinya Road - signage is in place - and need to allow an extra 20 minutes travel time.