While the ACT government sells its tram as a way to reduce congestion on Northbourne Avenue, its own analysis finds more cars, increased travel times and longer delays on the drive home from work.
Traffic signals will give priority to trams along the corridor from Gungahlin to the city, with traffic lights programmed to detect the approach of a tram and change to allow it through. But the analysis suggests changes might be needed to plans for the major Northbourne Avenue and Federal Highway intersections to reduce delays to other traffic.
The new documents also reveal the planned closure of the London Circuit carpark opposite the Melbourne Building during the four-year construction, when it will be taken over as a construction compound, with the loss of 250 carparks.
The documents put the start of construction in October 2016, coinciding with next year's election, with preliminary work - shifting bus routes, bridges and culverts, relocating pipes and wires - to start in July 2016. But a spokesman for Capital Metro Minister Simon Corbell said last night that didn't suggest a delay to the planned April start.
The government has released its 1600-page draft environmental impact statement, detailing the impact of the tram during construction and operation, not only on traffic, but trees, animals, buses, underground pipes and wires, and the impact of noise, truck movements and more.
The London Circuit carpark near the court buildings will be closed for four years, used as a compound for site vehicles and equipment during construction. The impact statement points to free space in parking buildings on Marcus Clarke street and the Canberra Centre for people to use instead.
Trams will run every six minutes during the morning and afternoon peaks, with the full journey taking 25 minutes - the same at peak and off-peak times. At the moment buses travel every three minutes at peak times, taking 28 minutes in the morning and 26 minutes in the afternoon.
The analysis anticipates many more vehicles in the corridor in 2021 as a result of the tram, which brings more apartments and businesses and results in worse delays than if the tram wasn't built. The average morning delay without the tram is pegged at 163 seconds in 2021; with the tram it will be 176 seconds. The average afternoon delay without the tram in 2021 is estimated at 126 seconds; with the tram, 203 seconds.
The car journey from Gungahlin to the city in the morning is expected to be faster than if there was no tram, taking 27 mins 31 secs in 2021, about four minutes faster than otherwise. But home again in the afternoon is expected to take seven minutes longer than otherwise, at 27 mins 52 secs.
The impact statement envisages some of the worst delays at intersections on the turn from Flemington Road to the Federal Highway, and around Dickson, with problems also expected where Barry Drive meets Northbourne.
It recommends more work on some of the traffic signal times to reduce traffic delays.
"[At] two intersections in particular, at the Federal Highway and Flemington Road, and Federal Highway and Barton Highway, which serve interstate functions, it is recommended that a better balance between general traffic and light rail may be necessary."
But it points out also that the traffic modelling by Arup might overestimate the problem because it envisages trams every five minutes and a travel time of 23 to 24 minutes, whereas the plan is for trams every six minutes and a travel time of 25 minutes.
Mr Corbell's spokesman said the modelling was a worst-case scenario to identify risks and clearly stated that it was "a conservative approach and will overestimate traffic impacts in a number of locations". It did not account for "increased mode shift to light rail", nor other traffic mitigation.
More people in the corridor would mean more traffic, and "having a world-class, reliable public transport system in place in these areas of growth will give people a viable alternative to using their private motor vehicles", he said.
"Although this modelling does show the possibility of additional delays at the Downer (Swindon St) intersection, Capital Metro is examining how these impacts could be further reduced."
- The draft environmental impact statement is open for public comment until July17.
LIGHT RAIL KEY FACTS
Construction compounds take over London Circuit carpark near the courts; site of visitor information centre on Northbourne Avenue, carpark opposite Exhibition Park.
About 60 truck journeys a day in 2017 and 2018 (36,000 movements across the two years); 7800 truck movements in 2016.
Standard construction hours 7am till 6pm Monday to Saturday; major intersection work, overhead wiring and oversize deliveries done outside standard hours.
Construction to use 74,000 cubic metres of concrete, 3.4 million litres of diesel, 9500 tonnes of asphalt, 100,000 metres of PVC ducts, 3000 tonnes of steel for rails, plus 9300 more for reinforcement and structural work.860 trees removed.
Construction to employ an average 500 people, up to 900 at peak times.
Weekend closure of key Northbourne intersections at Macarthur/Wakefield; Mouat/Antill; Barry Drive/Cooyong; Alinga (closed Friday 10pm til Monday 4am, adjacent ones not on the same weekends). Other intersections to be "sporadically closed" for up to two or four weeks, with diversions. Bus routes using the corridor and running across the corridor periodically disrupted.
Trams operate Monday-Thursday 6am-midnight, Friday-Saturday 6am-1.30am; Sundays 8am midnight. Trams every six minutes at rush hour, every 10 minutes 9am-4pm, every 15 minutes other times. Journey time 25 minutes Gungahlin to the city. 14 trams, each up to 33 metres long, with dedicated space for four bicycles. Top speed 70kmh.
Platform at each stop 33 metres long, capable of extension to 45 metres for extended vehicles; signalled pedestrian crossings to nearest footpath. Tram corridor 7 metres wide, widening in places to 10.4 metres, including outbound and inbound tram lanes and median strip.
Tram replaces trunk and express bus routes on Northbourne Avenue, the Federal Highway and Flemington Road.
An extra southbound lane to be built from the Barton Highway to Antill Street, 630 metres long.
Road changes include banning of turning across the median in some locations, including: Exhibition Park entrance, the Kamberra Wine Company on Flemington, the Yowan Golf Club on the Federal Highway, the netball centre on the Federal Highway, the southbound right turn from Northbourne Avenue to Bunda Street.
Seven electricity substations to be built along the route, each in a 12m x 4.5m building, at: Gungahlin depot, Flemington Road, Collaroy Street, Vicars Street, Barton Highway, Macarthur House and Mort Street.