Ontario Highway 4 History - The King's Highways of Ontario

King's Highway 4 is a major collector highway which passes through the heart of Southwestern Ontario. The highway was first established in 1920 when the road through London from Talbotville Royal to Elginfield was assumed as a provincial highway. Highway 4 was extended from Elginfield to Clinton in 1927. During the 1930s, Highway 4 was extended from Clinton to Flesherton, via Walkerton and from Talbotville Royal to Port Stanley. The final section of Highway 4 was designated in the 1970s between Flesherton and the Highway 24 Junction near Singhampton. Considerable portions of Highway 4 were lost to downloading in 1998, when nearly 65% (or about 175 km) of this highway was transferred to municipalities. The only section of Highway 4 spared from the downloading was from the Highway 3 Junction at Talbotville Royal to Clinton. The downloaded sections of Highway 4 retained their original route number after 1998, but they are now just municipal streets and county roads. The City of London now maintains most sections of Highway 4 lying within its boundaries, but the road is still signed as a King's Highway through the city.

Apart from London, Highway 4 passes through a predominantly rural area. The principal towns located along the original highway are Port Stanley, St. Thomas, London, Exeter, Clinton, Wingham, Walkerton, Hanover, Durham and Flesherton. The east-west section of Highway 4 from Walkerton to Singhampton is a very scenic drive, offering some of Southwestern Ontario's most pleasant rural scenery. Most sections of Highway 4 are two lanes, but the highway is four lanes approaching London. The former concurrent route of Highway 4 and Highway 9 near Walkerton is no longer signed. Services along Highway 4 are generally quite plentiful near London, but services become somewhat scarcer towards the northern end of the highway. The speed limit on Highway 4 is 80 km/h (50 mph), unless posted otherwise. Some of the downloaded sections of Highway 4 within Huron County are now posted at 90 km/h (55 mph). Please visit the Highway 4 Mileage Chart page for a list of mileage reference points along Highway 4.

Winter Driving Tip: Many sections of Highway 4 north of London are notorious for poor winter road conditions. The highway is sometimes closed during periods of poor winter weather between Elginfield and Singhampton due to blowing and drifting snow. Blowing snow will often result in zero-visibility conditions. The weather conditions on this highway can deteriorate very rapidly when snowsqualls blow in from nearby Lake Huron and Georgian Bay. On cold, windy days, it is a good idea to check the Road Closures and Winter Road Conditions pages on the Ministry of Transportation's Website, or verify road conditions by telephone at 1-800-268-4686 before using Highway 4 north of London.