Coach firm Aircoach is back on the road from Belfast to Dublin in a direct head-to-head with Translink.
After axing the service 18 months ago due to declining passenger numbers, the carrier - owned by Aberdeen-based bus company FirstGroup - has launched a new express service linking the two cities.
The route, direct from Glengall Street in Belfast to Dublin city centre via Dublin Airport, will operate 22 daily trips each way.
And Aircoach will also undercut its rival on price charging £20 return between the two centres compared to £20.85 for Translink.
However, unlike Translink, Aircoach's familiar blue coaches won't be serving towns like Banbridge or Newry which will cause some angst among commuters.
The journey time from Belfast to Dublin Airport is scheduled to be one hour 50 minutes and another 20 minutes to Dublin city centre.
When Aircoach was founded in 1999 by Irish entrepreneur John O'Sullivan, it broke the state monopoly on carrying passengers from Dublin centre to Dublin Airport.
The service was extended to other regional centres Cork and eventually a route to Belfast was launched in 2004.
It initially enjoyed commercial success.
However, Translink/Bus Eireann upped frequency on its cross-border service and in October 2010 Aircoach withdrew from the route with more than a dozen drivers being made redundant.
But Aircoach has re-entered the market following complaints from northern-bound commuters, particularly at Dublin Airport, who have often been left waiting for hours because the Translink service is already nearly full by the time it gets there from the city centre.
Aircoach said tickets are available for booking on its website while passengers can pay in advance or onboard the coach in either euro or sterling.
In a statement Translink said that, in partnership with Bus Eireann, it is operating 30 services a day between Belfast and Dublin Airport/Dublin city centre serving Lisburn, Banbridge and Newry.
"We offer a range of great value fares including a £55 family ticket and recently introduced new 74-seater coaches," it said.
"We would encourage more people to trial the convenience, quality and value of our services."