Keith Brown was forced to defend the £1.3bn project after Liberal Democrat MSP Alex Cole-Hamilton said the old bridge over the forth should be temporarily reopened to cars to ease congestion.
Queues of traffic have built up on the Queensferry Crossing in both directions on most days since it opened to the public, with transport authorities initially blaming “bridge tourism” for the problems.
Members of the public furious about their journeys being delayed have taken to social media to complain about the situation, with one regular commuter criticising the “horrendous” design of the new slip roads.
Leaders at the RAC also said it would be “sensible” to re-open the Forth Road Bridge to traffic.
Mr Brown said many drivers were still familiarising themselves with the bridge, which currently has a 40mph speed limit, adding that the problem had been exacerbated by people wanting to experience the crossing for the first time.
“We’ve never said this is only down to sightseers,” he told the BBC. “But even as recently as yesterday we had groups of vehicles travelling across the new Queensferry Crossing to have a look at it, quite naturally, then immediately turning round at the junction on the other side and going back again.
“That’s to be expected and it’s perfectly legitimate for people to do that, but that has produced some short-term pressures.”
The problems may continue for up to six weeks while the road approaching the north side of the Forth Road Bridge is remodelled. The old crossing will then open to buses and public transport, with the speed limit on the new bridge increased to 70mph.
Mr Brown said he hoped the remodelling work would be completed within four weeks. He also highlighted other initiatives to cut congestion, such as improving gantry signs and creating a “slicker” merging system.
Mr Cole-Hamilton said the ongoing delays were “having a material impact on people’s livelihood”, claiming that some commuters were losing up to half a day of work.
“If there is a material problem with the road layout of the bridge we have a release valve in the form of the Forth Road Bridge,” the MSP for Edinburgh West said.
Writing on Facebook, commuter Frazer Horswell accused ministers of “p*** poor road planning” and said the Queensferry Crossing should have been built to accommodate three lanes of traffic in each direction.
“I have never experienced such bad delays in my three odd years of crossing the bridge six days a week,” he said.
“Even at 9pm it had taken me an hour to do my usual 25-minute journey. The slip road coming on from Queensferry is a horrendous design and has no real merge point.”
Mr Brown added: “We always anticipated this huge level of interest. What we currently have is the same capacity as before - one bridge opened, 40mph, average speed cameras.
“I know it can be extremely frustrating but we have to get to the stage of being able to open both bridges and thereby alleviate the some of the pressure that is currently being felt.
“We have seen some improvements today...hopefully when it becomes less of a novelty it will improve even further.”
RAC roads policy spokesman Nick Lyes said: “With the opening of a new landmark in Scotland, an increase in traffic was always likely from day one simply because of
the novelty attraction of a new bridge – but nearly a week on there are still significant delays and drivers are starting to ask why. It’s hard to believe that all of the rush-hour delays are down to an increase in tourist traffic, but if it is then hopefully things should start to improve shortly.
“Re-opening the old Forth bridge to vehicles seems like a sensible solution if it is practical to do as it will increase overall capacity. Transport Scotland also plan to increase the speed limit from 40mph to 70mph. Clearly, neither action can come soon enough for the thousands of motorists that use the crossing every day.”