Chalfont St Giles, UK. 18th July, 2020. A temporary haul road is prepared for use in the construction of a ventilation shaft for the Chiltern Tunnel on the HS2 high-speed rail link. The Department for Transport approved the issuing of Notices to Proceed by HS2 Ltd to the four Main Works Civils Contractors (MWCC) working on the £106bn rail project in April 2020.