Waterford is a city in southern Ireland.
Almost all the traffic towards Kilkenny, Limerick and Dublin goes by this road because there is only one bridge crossing the river from the city center. Cross the bridge from the city center. At the end of the bridge, at the rondabout, turn left and continue walking about 5-10 minutes on the left side of the road. There is a sidewalk, it is very safe. After 5-10 minutes it will be a traffic light, close to a factory. There is a lot of space to stop a car.
I went there in june 2018 with a sign on wich I wrote "Clonmel", "Cahir" and "Limerick". The third car (20 seconds) took me until Cahir. It was very easy.
South towards Tramore
Towards Tramore, you can somewhat reliably hitch a lift on the R675 road's bus stop across from SuperValu Kilbarry. Most drivers will assume you're headed to Tramore, but be sure to specify with the driver.