Rail operator Transport for Wales (TfW) has announced more services will run on a Sunday on the Rhymney line.
From December, there will be seven extra services between Rhymney and Cardiff. Services to and from Caerphilly will increase from 16 to 45.
The move is part of a wider plan to boost Sunday services by 40% throughout Wales.
Customer Experience Director for Transport for Wales, Colin Lea, said: “A huge amount of hard work has gone into developing this timetable for our customers.”
Additional peak time services are also set to be introduced for the new timetable – due to be published next month.
Caerphilly Assembly Member Hefin David welcomed the new services for Sunday.
He said: “I have been pressing for improvements to the Sunday service since I was elected and it is good to see TfW have taken action.
“While I also look forward to additional peak time carriages from the new timetable, I will continue the dialogue with TfW to press for additional services for the Rhymney line.”
Meanwhile, refurbished trains that TfW had expected to use this year now won’t be ready until the new year.
“Engineering issues” have been blamed for the delay to the Class 769 trains.
The Class 769s are old electric trains used on Thameslink services in the south east of England. They are being converted for use with diesel engines meaning they can run on both.
TfW took over the running of Wales’ railways from Arriva in October last year.