Traffic lights at the junction of North Street and the High Street were switched off and a long stretch of pavement was closed on Monday to allow for more work on the Tesco development.
Much of North Street was also narrowed to one lane, leaving vehicles headed for the town centre fighting for space with construction lorries serving the building site.
Two temporary zebra crossings have been installed, at the southern end of North Street and the top of the High Street, but many motorists unfamiliar with the new layout were not stopping to allow people to cross.
Robin Sadler and Malcolm Cragg, of the Grenadier pub in the High Street, slammed the lack of signs warning pedestrians and drivers of the new road layout and its associated works.
Mr Sadler told the Gazette, "Someone is going to get seriously hurt.
"There are no clear signs, people are just walking out into the traffic.
"At the rush hour in the morning you've got school traffic and elderly people getting off buses.
"If nothing is done there will be an accident, I guarantee it."
Mr Sadler added people would have to cross FIVE roads to reach his pub from the Tesco side of North Street — a walk that was normally possible along one footpath.
"You've got to cross North Street and then cross the High Street at the new zebra crossing.
"You then have to cross Vicarage Lane, walk right up past the shops and cross Battle Road and then cross London Road at the lights to get to our side of the road. People just won't do it."
A spokesman for East Sussex County Council said, "We have been talking with Tesco and its contractors about the work on North Street.
"We agreed the contractor would install a temporary zebra crossing in the High Street and temporarily relocate the zebra crossing in North Street to help pedestrians cross the road safely while the footway is closed.
"We also agreed the contractors would follow county council guidance, put up notices of the works and inform Sussex Police and other emergency services.
"Council officers will be visiting the site during the week."
On Monday afternoon, dozens of pupils from Hailsham Community College were seen having to dodge traffic, including buses, as they crossed roads on their way home from school.
Principal Lesley Farmer said the school was 'concerned' about the volume of traffic. But she told the Gazette, "With regard to this development, we have had no specific feedback from parents or students."
The Cuckoo Trail was also closed briefly on Monday as part of the works but contractor Kier admitted this proved unpopular with local residents and it was reopened.
A spokesperson added, "The footpath has now been diverted to keep the public at a safe distance from the construction activities. This diversion will be in place throughout the contract, which is expected to complete by late autumn."
ABOVE: The roadworks (e19103j)
andrew.raeburn@trbeckett.co.uk