If you are a York Region commuter, this may be one lane closure you greet with open arms.

Starting Dec. 19, for approximately three nights, northbound centre lanes will be temporarily closed along Yonge Street to enable geophysical testing for the much-anticipated Yonge subway extension.

The 7.4-kilometre extension of the Yonge subway Line 1 is expected to eventually extend from Finch Station in Toronto to the Richmond Hill/Langstaff Gateway Urban Growth Centre at Highway 7 in Richmond Hill.

Work will begin from 7 p.m. to 5 a.m. Dec. 19/20 on the north side of Steeles Avenue to the south side of Thornhill Summit Drive.

The following night, from 7 p.m. to 5 a.m. Dec. 20/21, work will take place on the north side of Summit Drive to the south side of Kirk Drive.

Work continues Dec. 21/22, from 7 p.m. to 5 a.m. on the north side of Kirk Drive to north side of Langstaff Road East.

All lanes that are closed for work activities will reopen immediately following the completion of the work. Access to businesses and properties near the work areas will be maintained and paid duty police officers will be on-site to help guide traffic as needed.

Starting in January 2019, crews will kick off geotechnical investigations.

This work involves borehole drilling every 100 metres from Finch Avenue in Toronto to Highway 7 in Richmond Hill on the right-of-way as well as private property locations.

As part of this exercise, the project team will contact property owners along the corridor for permission to access.