Hold on tight.

Recent drone video for the Highway 401 and 409 Rail Tunnels project takes you into one of the tunnels, right beneath the cars travelling above.

The new tunnels will provide space for two additional tracks in the future, supporting GO Expansion for two-way, all-day train service on the Kitchener GO line.

Take a look at the work happening, right below the highway.

Crews are excavating and constructing two tunnels, all while traffic on the 401 and 409 highways continues.

Interestingly, the large orange tube at the top of the tunnel provides fresh air supply, which is constantly being pumped into both tunnels.

It’s easy for those away from the work site to forget that Metrolinx is working to deliver this project under 21 live lanes of traffic.

For more information or sign up for e-newsletter updates by emailing TorontoWest@metrolinx.com.