The road will be closed to traffic for nine months
There are calls for a temporary road crossing as a bridge over a railway line is replaced in Conwy.
Maesdu bridge at Llandudno has now closed, and the new bridge will take about nine months to build.
A plan for a temporary pedestrian crossing has been welcomed by local businesses, but it also wants vehicle access.
Conwy council has arranged a shuttle bus for the duration of the works and apologised for any inconvenience.
"I'm delighted about having a new bridge, but not happy with the nine months it is going to take," said David Williams, chairman of the Llandudno Hospitality Association.
"We are pleased about the footbridge, especially for the children who attend nearby schools, but we want it lit at night and covered by CCTV," he added.
Mr Williams said that business in West Shore would be affected by the road closure, because part of the area would affectively become a cul-de-sac.
He said that because of this it would have been better if a temporary road crossing had been arranged, especially as the construction period could exceed the expected nine months.
"These days the army throw them up [temporary bridges], and the council could have asked if they would be prepared to do it as an exercise," he said.
Malcolm Currie, group engineer with Conwy council, said the A546 would be closed to all vehicles and pedestrians from the junction of Maesdu Road to the junction with Alexandra Road, with diversions in place.
He said one of the first jobs will be to put up a temporary footbridge over the railway line so that pedestrians can continue to get to and from Llandudno Hospital and Ysgol John Bridge.
He said the footbridge would be open within the first couple of weeks of the contract.
Demolition of the existing bridge is scheduled to start on Sunday, 15 November, when the Llandudno Junction to Llandudno railway line will be closed for five days.
"We realise that there will be some disruption whilst work takes place and we'd like to apologise for any inconvenience caused by this essential work," Mr Currie added.
Arriva Trains Wales said there would be a half-hourly shuttle service, via Deganwy, between Llandudno Junction to Llandudno.
Rail tickets would also be accepted on local Arriva bus services for the period of the rail closure between 16 - 19 November.