The Grange, between Doyle Road and Brock Road, shut yesterday for four days while Geomarine undertakes work for Guernsey Water, and Trant for Guernsey Electricity.
Gold accredited tour guide Sylvia Brouard said she was concerned about the problems the roadworks would cause.
‘It’s just shocking really to have two main roads into town closed on a Friday,’ she said.
‘I feel quite strongly. Nobody should even try going into Town on Friday.’
South Esplanade and Le Val des Terres will also be shut on Friday for a charity sporting event from mid-morning until early evening.
A Traffic and Highway Services spokesman said staff were aware of the two planned closures.
‘Traffic and Highway Services has spoken with Guernsey Water and Guernsey Electricity who are both due to work on the Grange between Tuesday and Friday,’ he said.
‘Every effort is being made to complete the works and reopen the road in advance of Friday.
‘On Friday, the Val des Terres will close for the Hellvetia Challenge charity event, however this road closure will not begin before 10.30am, meaning morning commuters can still use this route.
‘We will provide updates ahead of Friday so road users can plan their journeys, and we would ask them to allow extra time. These two closures will not affect access for people on foot or bikes.
‘We ask them also to note that seasonal short term parking at South Esplanade, by Havelet slipway, will be swapped to the landward side of the road on Friday. This is due to approximately half of the seaward side being used in connection with the event.’
An extra challenge will be that parking will be suspended on Albert Pier as the cruise ship Celebrity Silhouette is set to arrive at 10.30am with up to 2,900 passengers.