In 1897 the Queen Victoria Jubilee Bridge, a single-arched stone bridge, was opened. However by the early 1920s, with increasing numbers of motor vehicles, the area was becoming notorious for traffic congestion. The stone bridge was proving too narrow for the road's larger vehicles.
The New Jubilee Bridge, a steel rolling bascule bridge, was opened by the Ministry of Transport for the newly named A494 in 1926. The original bridge was demolished although the stone abutments can still be seen today. The New Jubilee Bridge then remained the sole road crossing until the late 1950s. By then traffic levels had again risen making this bridge obsolete.
The Queensferry bridge over the River Dee—on the main route from the north in Wales—is barely wide enough for two lines of vehicles, and five-mile traffic jams are normal.
In the 1960s, a dual carriageway and new bridge was constructed by-passing the old route through Shotton and Queensferry. This route had remained unchanged until an upgrade in 2004.
This section forms part of the North Wales coast route between Holyhead and the M56 motorway. The section of the A494 north of the River Dee was upgraded to 4-lanes plus hard shoulders in each direction in 2004 as part of a wider scheme, which upgraded the A550 as well, although not all of the lanes on the A494 have been opened.
The next stage of the scheme was to widen a 2.5 mile stretch of the A494 from the River Dee up Aston Hill to the Ewloe Interchange, the junction of the A55 and A494, to 3 and 4-lane plus hard shoulder standard.
In April 2006, local residents living at Aston Hill, part of the proposed route, began a campaign to oppose any further widening of the A494. After 15 months, protesters' high-profile message had garnered more than 2300 individual letters and numerous petitions rejecting the proposals. A Planning Inquiry was held in September - October 2007.
In March 2008 the proposals (in entirety) were ordered to be scrapped by the Ieuan Wyn Jones, Deputy First Minister, responsible for Transport at the Welsh Assembly.
"In reaching my decision I have taken account of the concerns raised by the inspector that the overall size of the scheme would have a significant impact on the landscape and would affect walking and cycling routes. I have also noted [the planning inspector's] remarks that while he considers that this section of the A494 will need some form of improvement in the foreseeable future, he considers that the scale of the scheme as originally proposed is greater than required." Deputy First Minister Ieuan Wyn Jones
This part of the A494 will remain a two-lane dual carriageway and the speed limit will be 50mph.
The decision has left a question mark over the future of the remaining upgrade at Ewloe Interchange.
Resentment also remains within the Aston Hill community as thirty households were evicted from their homes earlier in the scheme. These houses were earmarked to be demolished to make way for the road-widening works. No decision has been made about the future of these properties.
South of the Ewloe interchange, the A494 is entirely single-carriageway trunk road, with much lower traffic flows than the A494 to the north of the Ewloe Interchange. This section is approximately 25 miles (40 km) in length. There is a bypass for Mold before the road runs through Ruthin and several smaller villages before meeting the A5 at Corwen at a T-junction. There follows a short concurrency with the A5 at this point.
Despite being the most important road in this area, much of the traffic follows the largely parallel A5104 between the A55 and Corwen.
The A494 emerges from the concurrency with the A5 at Druid, heading south-west for a further 27 miles (44 km) to the town of Dolgellau. After a few miles from Druid, it runs through the town of Bala, before meeting Llyn Tegid. As it does so, the road enters the Snowdonia National Park. It runs along the side of the lake for 4 miles (6 km), after which it largely follows the Afon Wnion with the famous mountain Cadair Idris in front, before terminating at Dolgellau at a T-junction with the A470, itself an important trunk route in Wales.