Work has started on a £750,000 roadworks project around the former Sussex House site in Crawley High Street.
The work is expected to go on for 15 weeks.
The aim is to create a pedestrian friendly area and renew the traffic light system at Pegler Way and The Boulevard with the use of modern LED technology.
The investment has been made by Land Securities, the developer of the multi million pound regeneration of the site.
The developer is building a Morrisons supermarket, a 110-bed Travelodge hotel, restaurants and a 500-space town centre car park.
The highways work, approved by West Sussex County Council (WSCC), will provide high-quality paving on a wide pedestrian area with enhanced street lighting in front of the new development.
A designated cycle park will also be made available through the development.
During the work, traffic will be kept moving without the need for temporary traffic signals, but will be constrained to a single lane around the one-way system.
Should a road closure be needed for final road resurfacing, then advance warning signs will be erected at least seven days beforehand.
WSCC’s Cabinet Member for Highways and Transport, Pieter Montyn, said: “We are committed to working with Land Securities to deliver these improvements to Crawley town centre as part of the new development on the former Sussex House site.
“The investment will mean an improved area for pedestrians and indicates a commitment to improve Crawley town centre for the long term.”