<map lat='51.887934991741986' lng='-8.487281799316406' zoom='12' view='0' float='right' width='370' /> Cork is the second biggest city in Ireland. Cars registered in Cork have registration plates with letter C.
Get the number 8 bus to Mayfield. Walk down the hill away from the main supermarket for 10 minutes. You will arrive at two petrol stations (Topaz and ?). You can ask around there for people headed east. If they're going east, but in the wrong direction after the Dublin and the Waterford road are separating, have yourself dropped of at the second roundabout (works great for Dublin, don't know about Waterford).
You could also walk from the city quite easily. Head up to McCurtain Street and go all the way past the train station and out that road until you come to a space where cars can park (20 minutes to half an hour walk) (Lower Glanmire st, 82 seems to be the exact place, 5 quick rides got in two weeks. summer 2017) This is a good spot to hitch and you'll get lifts to East Cork or Waterford quite easily.
Go to the Blackpool shopping centre on the North side of the city. This can be reached by the number 203 bus (2017) from Cork City Centre (Merchants Quay) for around 2.20 Euro (2017). From here, you walk up the motorway for 10 minutes until you reach a bus shelter on the left hand side with the massive area. Also, try the traffic lights all along this road. We waited for 20 minutes with a sign at this spot and got a lift to Limerick city.
The petrol station by Dino's chip shop in Blackpool is also a good spot for a lift to Limerick.
Go to traffic lights after Bandon roundabout. Served by bus 8 and 19 to Bishopstown. Leads to N22 motorway.
Another spot is the intersection of Victoria Cross (N71) and Carrigrohane Road (N22). Take bus 208 towards Boherboy Road and get off at Victoria's Cross (it'll say Wilton Road on the bus screen; ask the driver when to get off). Walk back maybe 50 meters to the intersection you just turned from, turn left onto Carrigrohane Road in the direction of the sign for Killarney, and walk 200 meters until you see a tall building on your left. There will be a bus stop by a traffic light with space for drivers to pull over. A friend and I waited no longer than three minutes before we were picked up.
Southwest towards Bandon, Clonakilty
Go to the Bandon roundabout. Served by bus 208 and 19 to Bishopstown. Leads to N71 motorway. You can get off the 208 at the stop for Hawks Road, hop off the bus and go left then right down Hawks Road. Turn right at the end of this road and follow the road to the left out past the Bandon roundabout to the Amber petrol station. There are several places to stand by the station and this is the best place to hitch from if it's late as there are street lights.
You could also stay on the 208 bus until it's last stop (Marymount Hospice) and get off here. Walk through the Hospice to the entrance on the Waterfall Road, turn right and hitch from the grassy verge on the side of the road. This is a country back road that goes all the way to Bandon. This is not a great place to stand if it's dark.