However, the cones and signs which were put in place "as a first response" a week ago were found in a ditch the next morning.
"So we put up marker posts and double-nailed them down in case strong winds or vehicles passing close to the cones may have caused them to be knocked or blown over.
"However, when our staff checked the area after last weekend, not only were the cones in the ditch again, the edge marker posts appeared to have been ripped out and thrown down next to them.
"The only remaining warning indicator of the slip was the 'shoulder closed' sign."
Mrs Clark said it was vital that people left the warning signs where they were.
"We would ask that people take note of and respect the NZTA's warning signs and markings in any maintenance area. Interfering with them creates a safety risk and people must stay clear of them at all times," she said.
The Transport Agency had also installed a bund, or embankment, on the slope to keep water away from the slip area. "The bund itself is about 40m long but the slip's length is considerably shorter than that."
She advised that buses which used that section of the state highway would continue as normal and that the existing bus stop before the slip area was still in use.
"Our contractors have assured us that the bus stop site is far enough away from the roadworks to avoid disturbing bus movements until road repairs are completed," said Mrs Clark.
However, car drivers dropping passengers off in that area should be "extra cautious" because there was limited parking room around the bus stop itself.
"A safer option might be for car drivers to drop off their bus passengers in Lorenzen Bay Rd - a side road beside the bus stop on the same side as the road," Mrs Clark said.
The Transport Agency was monitoring the slip and had sought geotechnical engineering advice on work needed to restabilise the area.
Mrs Clark said once that information had been obtained, repair work would begin as soon as possible to get the road shoulder back in action.
