The Office of Rail & Road (ORR) is the regulator for Network Rail, they are currently overseeing funding for Control Period 6 (CP6) – from 1 April 2019 to 31 March 2024. In Northern Ireland, Northern Ireland Railways (NIR) both owns the infrastructure and operates passenger rail services. The Northern Ireland rail network is one of the few networks in Europe that carry no freight. It is publicly owned. NIR was united in 1996 with Northern Ireland's two publicly owned bus operators – Ulsterbus and Metro (formally Citybus) – under the brand Translink. In Northern Ireland there is of track at gauge. of it is double track. Eurostar operates trains via the Channel Tunnel to France and Belgium and the joint Northern Ireland Railways/Iarnród Éireann Enterprise trains link Northern Ireland and the Republic of Ireland as well as one Iarnród Éireann train per weekday in the morning from Dublin to Newry. Three cities in the United Kingdom have rapid transit systems. The most well known is the London Underground (commonly known as the Tube), the oldest rapid transit system in the world (opened 1863). Another system also in London is the separate Docklands Light Railway (opened 1987). Although this is more of an elevated light metro system due to its lower passenger capacities; further, it is integrated with the Underground in many ways). Outside London, there is the Glasgow Subway which is the third oldest rapid transit system in the world (opened 1896). One other system, the Tyne & Wear Metro (opened 1980), serves Newcastle, Gateshead, Sunderland, North Tyneside and South Tyneside, and has many similarities to a rapid transit system including underground stations, but is sometimes considered to be light rail. Urban commuter rail networks are focused on many of the country's major cities:  They consist of several railway lines connecting city centre stations of major cities to suburbs and surrounding towns. Train services and ticketing are fully integrated with the national rail network and are not considered separate. In London, a route for Crossrail 2 has been safeguarded. Tram systems were popular in the United Kingdom in the late 19th and early 20th century. However, with the rise of the car they began to be widely dismantled in the 1950s. By 1962 only the Blackpool tramway and the Glasgow Corporation Tramways remained; the final Glasgow service was withdrawn on 2 September 1962. Recent years have seen a revival the United Kingdom, as in other countries, of trams together with light rail systems.