Emergency services are responding to a gas leak at the intersection of Omahu Rd and the Hawke's Bay Expressway.
Fire communications shift manager Chris Dalton said two fire trucks were called to the gas leak at the busy intersection at 1.25pm.
A police spokesperson said police were assisting with traffic control and were not needed for any evacuations.
Police advised the roundabout was blocked while contractors deal with a gas leak with only one lane in use and congested traffic.
"The work is expected to take some time so motorists are advised to avoid the area and use alternative routes."