NorthConnex (Sydney) was built as a more efficient and safer alternative to the notoriously congested Pennant Hills Road - previously a key freight route for transporting goods across Sydney.
Before the 9km NorthConnex tunnel opened, in October 2020, around 9,000 heavy vehicles used Pennant Hills Road every day, moving goods from Sydney's southwest to the city's northeast.
The majority of this traffic now uses NorthConnex.
As well as making Pennant Hills Road a safer driving experience for local road users, the significant diversion of traffic on to NorthConnex has improved air quality in the local area. Independent monitoring at six locations along the Pennant Hills Road alignment found some impressive improvements to local air quality.
For example, at one roadside monitoring site (the Thornleigh Golf Course), nitrogen oxides (NOx) concentrations were about one third lower than they were in 2020, prior NorthConnex's opening. (NOx are 'greenhouse gases' produced by internal combustion engines.)
And average measured carbon monoxide emission rates are also consistently lower than predicted rates.
This means people living and working in the area are enjoying cleaner air than they were four years ago. Plus, locals (and all road users) are saving up to around ten minutes in travel time by choosing NorthConnex over the alternative route during peak periods.
