To make the estate more profitable, Griffiths decided to improve the transportation links from the site to the newly opened Glamorganshire Canal.
Griffiths first built a tramroad from the Hafod Estate to the town of Newbridge, now known as Pontypridd, and there bridged the River Taff.
[2] The tramline, which was serviced by horses pulling wagons along its length, was opened for business 29 September 1809,[2] becoming the very first transportation link into the Rhondda Valley.
[3] Griffiths himself denied owning a coal level in a series of replies to a Select committee to the House of Commons of the United Kingdom in 1810.
[7] On Griffiths' death the rights to the Trehafod Estate passed to his family and was successfully deep mined by John Calvert in 1851.