A relief road is to be opened in east Belfast next week following the introduction of a new bus lane in the Titanic Quarter.
Belfast Harbour said they are "acutely aware of the significant disruption" during peak evening traffic.
The new bus lane will accommodate Belfast's new Glider system.
Belfast Harbour said it is hoped the opening of an "interim relief road" linking the Queen's and Sydenham roads will help alleviate travel disruption "in the short term".
They added: "Belfast Harbour and Titanic Quarter Ltd remain fully supportive of a functioning Belfast Rapid Transit system in the city and continue to engage with the Department for Infrastructure and Translink to find solutions that will resolve the problem and reduce congestion for all those who work, live and visit Titanic Quarter."
The Glider buses which will use the lanes have been described as "a tram on wheels" and will run approximately every seven to eight minutes, linking east Belfast, west Belfast and the Titanic Quarter with the city centre.
But the Department for Infrastructure (DfI) said delays had been "greater than anticipated" and it would revise traffic light timings in the area.
On Thursday, Titanic Quarter commuters told BBC NI's Newsline programme the traffic problems are "absolutely horrendous".
"It's a bottleneck - hundreds and hundreds of cars," said one woman.
Another told the programme: "A usual journey for me would be 15, 20 minutes. It could be anything from 50 minutes to an hour now."
The DfI said: "At peak times, the road network in Belfast is at full capacity or over capacity. With new development the number of cars on our roads will continue to grow and this will make the situation worse if we do not act."
A spokesperson told the BBC that "variable messaging signing" had been added and changes had been made to traffic signalling in the area in an effort to improve the flow of traffic.