Thursday, 17 December 2015

Arterial and through roads

The largest roads in a city are the arterials and through roads. The Dutch classify their roads as an access road, a 30 km/h (these are all for urban areas) zoned road that gives direct access to homes, businesses and other important destinations, through roads, for the fast traffic in high volumes at high speed, and distributor roads, which connect the two other types. I am going to talk about the distributors a bit but mainly the through roads.

Distributors have cycle tracks, completely separate from motor traffic, as they are a different type of roadway with a higher speed and more volume, except for a small number of kilometres where a cycle lane might be used. If it is used, they must be at least 1.7 metres wide, they should be between 2 and 2.5 metres in width, preferably with an extra buffer of .5 metres. What the buffer is is the subject of debate, but options such as paint and flex posts are presented. Cycle tracks are supposed to be used where possible. Retrofitting a newer collector could have cycle lanes and removal of one lane of parking, plus a speed limit of 40 km/h, but a reconstructed street would switch the location of the tree buffer and the cycle track and put parking directly next to motor traffic. And cycle tracks must be at least 2 metres wide, 3.2 metres for a bidirectional track, and should be 2.5 metres for the one way and between 3.5-4 metres in width depending on the kind of cycle track. The buffer, which needs to be a curb/median to be a proper cycle track, would need to be at least 35 cm next to moving traffic and 80 cm next to parking cars, with 1.5 metres as the standard width for being near 50 km/h traffic, and 2 metres for being next to 60 km/h traffic+.

I've talked about that before, but now, the through roads. These are the the largest roads that you can build. In the Netherlands, these are generally the freeways, roads with a blue background and white car on the entrance to them, ring roads, bypasses and most roads with 70 km/h speed limits, plus those with more than 1 lane per direction not counting turn lanes. These also tend to have a dashed white line very close to the right edge of the road, plus any road that has a significant amount of grade separation, minus separation from railways. They are also usually the ones linking entire districts to other places. Like Gateway Boulevard linking Heritage Valley to downtown. In Edmonton we have a bit of confusion with this because many of our four lane divided arterials tend to functionally behave like distributor roads. They link neighbourhoods to other neighbourhoods and to through roads. If you look at a map of a Dutch city, I will use Den Bosch as my example, the Zanzuidergweg is an example.

So what could this network of through roads look like?

The following roads would become the through roads, and any upgrades are described that would make it a good through road. The speed limit is also described, assuming the best possible conditions for traffic. Also, as much as possible, at an interchange with the main route going under or over on a bridge or tunnel, the remaining intersections changed to roundabout control. Electronic management system mean variable speed limit/lane use signs, ramp meters if there are freeway style ramps on non free flow interchanges, traffic flow sensors and overhead message boards. Also note that any bus stops also get an inlet for them to stop at, with less disruption. Any parallel cycleways/sidewalks will have a solid and wide buffer, preferably at least 3 metres wide, at least 1.5 metres of width. At speed limited areas above 50 km/h, noise walls and visual screening will be used to shield cyclists and pedestrians from motor traffic, and any crossings will be either grade separated or signalized above 50 km/h. Crossings of the through road itself should be grade separated where possible at speeds above 50 km/h. Minor access streets closed off and traffic diverted in some way to another route, building service roads if needed. Parclo interchanges without a right turn bypass lane on all arms will gain a right turn bypass ramp. At interchanges, any unsignalized crossings for pedestrians or cyclists need to be removed and replaced with an underpass or overpass.

Yellowhead Trail. Grade separated and built to freeway standards. 120 km/h (130 outside of Edmonton). Electronic management system.

Whitemud Drive. 120 km/h (except through river valley, 90 km/h is used, and west of Anthony Henday, where 130 is used). Electronic management system. Extensions to Acheson via highway 60. Interchange with Anthony Henday in the west is upgraded to a stack interchange. Railway underpass on the ramps with Gateway Boulevard.

Anthony Henday Drive. 120 km/h. Electronic management system. Completion of the NE ring road. Ellerslie Road has access to Anthony Henday. 111 St also fully accessible from Gateway Boulevard. 91 St interchange upgraded to full cloverstack or stack. Terwillegar Drive upgraded to stack or cloverstack. 97 St interchange upgraded to cloverleaf. St Albert Trail interchange upgraded to cloverstack. Upgraded to 3 lanes minimum all the way around.

Sherwood Park Freeway. 100 km/h. Electronic management system. Interchange with Anthony Henday changed to stack. 71 and 73 St intersections closed.

Terwillegar Drive. 120 km/h, 130 south of Anthony Henday. Electronic Management System. Grade separated and built to freeway standards. Extended south to bypass Leduc to the west and south, to provide a bypass for Alberta Highway 2A.

Ray Gibbon Drive. Upgraded to freeway standards. 130 km/h. Electronic management system. Interchange with Anthony Henday upgraded to stack.

St Albert East Bypass. 70 km/h. 4 lane divided arterial with cloverstack at Ray Gibbon Drive and diamond at Sturgeon Rd, cloverleaf at Anthony Henday Drive. Signalized intersection at Valour Ave and Bellrose Drive using the continuous flow style with bicycle and pedestrian underpasses (the continuous flow is a pretty clever way of increasing capacity, but is not suitable for the dense intersections like in Downtown and Strathcona. Bicycles and pedestrians should be grade separated in all but the most exceptional cases, in which case full signal separation is essential). It goes around St Albert well to the east, linking with HWY 2 at township road 544, and at Anthony Henday Drive at 127 St. Electronic management system.

170 St. 70 km/h. 6 lane divided arterial with diverging diamond interchanges at Yellowhead and Whitemud. Underpass under Mayfield Rd and Stony Plain Rd. Underpass at 87 Ave, with diamond interchange. 95 Ave/170 St gets a continuous flow intersection. Remaining side accesses, driveways and minor side roads are closed off. Electronic management system.

St Albert Trail/Groat Rd. 4-6 lane divided arterial. Trumpet interchange with Anthony Henday Drive. 70 km/h. Electronic management system. Intersection with Campbell Rd/156 St closed, in favour of a west extension of 153 Ave and traffic using 137 Ave. 137 St/St Albert Trail gets a diamond interchange. Yellowhead Trail/St Albert Trail interchange becomes a diverging diamond interchange or gets a pair of turbo roundabouts (with bicycle overpasses). 118 Ave and 111 Ave intersections become standard shape signalized intersection looking like this: Inner Ring Road Groningen.

University Ave between Groat Rd and 114 St. 50 km/h. LRT gets an underpass if possible under University Ave. Right turn onto 114 St converted into a protected prohibited function. Intersection converted to Dutch standard traffic light controlled intersection. Median added between the two directions. Roundabout at University Ave and 87 Ave converted into a regular roundabout, with a spiral lane pattern, a bypass lane for Groat Rd EB traffic to continue without interaction with motor traffic, with a light controlled pedestrian and bicycle crossing and low waiting times. Dedicated left turn lane for WB University Ave traffic onto SB Saskatchewan Drive, right turn from WB to SB with tighter corner radius and median enforcing the turn lane, plus a light controlled pedestrian and bicycle crossing. 117 St access closed to motor traffic, light controlled pedestrian and bicycle crossing. 119 St access closed. Electronic management system.

91 St. 100 km/h between Anthony Henday and Whitemud Drive, 70 between Whitemud and 63 Ave. Diamond interchanges built at 23 Ave and 34 Ave, flyunder for 28 Ave and 39 Ave. Cloverleaf completed interchange at Anthony Henday Drive, Diverging Diamond interchange or turbo roundabout with bicycle overpasses at Whitemud Drive. Railway underpass just south of 63 Ave. Turbo Roundabout installed at 63 Ave and 91 St, with bicycle underpass under 63 Ave. Electronic management system. Continuous flow intersection installed at 51 Ave. Other side accesses moved onto service roads. Underpass under intersection for cyclists crossing both 51 Ave and 91 St. May get 6 lanes.

Gateway Boulevard/Calgary Trail. 130 km/h south of Ellerslie Road, 100 km/h south of 30 Ave, 70 km/h south of Whitemud Drive. Left two lanes divided from main part of roadway with median between Whitemud Drive and 30 Ave, local lanes limited to 50 km/h. Only local lanes have access at Solo Southpark and Gateway Boulevard and only local lanes have access at Wild Wings and Calgary Trail and traffic lights are removed with right in right outs at 31 Ave and 42 Ave. 34 Ave gets a grade separation from railway line, and only local lanes are allowed to turn left at 34 Ave. Electronic management system.

HWY 15. 130 km/h between township road 522 and 153 Ave, 100 km/h between 153 Ave Yellowhead Trail. New bypass around Fort Saskatchewan to the North, partially paralleling HWY 825. Electronic management system. Complete grade separation and construction to freeway standards except at Yellowhead Trail, where an at grade junction is used. No interchange with 50 St and Manning, both roads continue as separate south to northeast and southwest to northwest roads, not intersecting diamonds at 153 Ave and 137 Ave interchanges, and grade separation in the rural northeast. Y interchange at existing highway 15 join up point. Yellowhead trail gets a diverging diamond interchange with Yellowhead as freeflow. Cloverstack at Anthony Henday. Flyovers at 167 Ave, 144 Ave and Hermitage Rd, with remaining accesses either right in right outs or simply closed.

114 St beginning at University Ave/113 St/61 Ave/63 Ave/Argyll Road. 50 km/h. Divided 4 lane road all the way. Electronic management system. New roundabout at Belgravia Rd, 60 Ave and 111 St with bicycle and pedestrian light controlled crossings and completely separate paths. 65 Ave becomes transit only and the turn lanes on 113 St become bus only, and get completely separate light stages, also for cyclists and pedestrians coming on their own paths to cross 113 St. 109 St intersection with 61 Ave gets turned into a simpler four way intersection, the south arm only open to bicycles, pedestrians and buses. 104 St/Gateway boulevard/63 Ave each get new separate traffic lights for turning traffic, as does 99 St/63 Ave. 75 St and Argyll Rd intersection could either become a pair of T intersections or one diverging diamond interchange with 75 St being freeflow. 83 St and Argyll Rd gets a T junction treatment. Underpass at 76 Ave.

75 St. 70 km/h (100 km/h between 98 Ave and Fort Rd. Electronic management system. Divided 4-6 lane road. New diverging diamond or turbo roundabout interchange at Whitemud Drive and Yellowhead Trail. New ramps for the partial diamond at 106 Ave interchange. Flyover for 101 Ave. New turbo roundabout with bicycle underpasses at 98 Ave (could be a diamond interchange, but it would need about 40-50 metres of extra right of way to do it. 75 St would in that case be the free flow road. Continuous flow intersection at Roper Road and possibly at Fort Road if space permits. Otherwise it will be a standard intersection with turns separated out. Closure of minor cross streets including 51 Ave. Grade separation of railway crossings. Diamond interchange at 90 Ave and a continuous flow intersection at Whyte Ave.

River Valley Rd/Rossdale Rd/97 Ave/98 Ave. 50-70 km/h. Divided 2-4 lane road. Electronic management system. Interchange improvements with Groat Rd. Minor side streets connected to Fortway Drive by a 30 km/h access road and links between side street and River Valley Rd removed. New 30 km/h access road links water treatment plant to 96 Ave and removes the link to Rossdale Rd. Simultaneous green and separating turn movements from through movements implemented at 97 Ave and Rossdale Rd/104 St. 98 Ave service road to Muttart Conservatory access to 98 Ave main arterial removed. Conners Rd gets new ramp towards 98 Ave EB. Service road 98 Ave gets a spur to the neighbourhood around the Bennet Centre. Traffic circle at 84 St and 98 Ave changed to a modern roundabout with spiral lane marking and raised ridges, and gets a light controlled set of pedestrian and bicycle crossings or underpasses for them. 79 St intersection is closed to motor traffic with a light controlled bicycle and pedestrian crossing.

Fox Drive/Belgravia Rd. 70 km/h. Turbo roundabout built at Fox Drive and 122 St with a bypass lane for right turns and the through movement of Belgravia Rd WB to Fox Drive WB. 142 St/Fox Drive becomes a right in right out, and the access to Fort Edmonton becomes a traditional T intersection, equipped with separate turn signals for the different directions. Access to Keillor Rd is created towards Fort Edmonton Park Rd, and removed from Fox Drive. Access to 116 St removed from Belgravia Rd. Electronic management system.

97 St/167 Ave/82 St. 120-50 km/h. Electronic management system. Organized as a 2+1 road coming from the North of Edmonton with a median between the two directions, alternating the extra lane direction. Anthony Henday Drive interchange upgraded to a full cloverleaf. Access to 176 Ave removed, and bike path running diagonally places in an underpass. Business access just south of 176 Ave removed, and connection to Elsinor Road installed. Speed limit drops to 70 km/h at 137 Ave. Double left turn onto 137 Ave from 97 St and again from 82 St to 137 Ave. Business access removed, their function taken over by nearby collector roads. Minor side street access closed for motor vehicles, pedestrians get a light controlled crossing. 137 Ave has a 70 km/h speed limit. On 82 St, speed limit is 50 km/h. minor side streets are closed for motor traffic. At 127 St, intersection gets simultaneous green and separate signal stages for turns, away from the through traffic movement. At Yellowhead Trail, street gets diverging diamond.

Ok, so with all that, why would I upgrade and sometimes build from scratch, such large roads? A primary reason is to build the bypasses that make the volumes for downgrading other roadways possible. Another primary one is safety. A number of these roads have bad safety records. The Dutch are planning to build a motorway through Vught because of it's bad safety record, and also because of traffic capacity reasons. The Yellowhead is a particularly dangerous route on the parts that isn't up to freeway standards yet. And the freeways we do have possess capacity issues characteristic of most other freeways in urban areas. Germany saw great results when the electronic management system was applied to their roads. And when you factor in the dramatic reduction in conflict points, using several roundabouts, diverging diamonds and continuous flow intersections, traffic lights controlling which direction goes when, and not allowing conflicts, it becomes even safer. Several railway crossings would be grade separated, further reducing the impact of trains, and permitting more freight and potentially passenger traffic on those rails, and it makes it impossible to impact a freight train so long as you stay on the road.

I also needed to provide alternate routes to important places. I don't want through traffic using Whyte Ave. What would work as a bypass would be going around it on Argyll Rd and 61/63 Ave, plus 113/114 St. It needs to be a fast and high capacity route to work well for this though. Which is why 170 St in my plan would have so much grade separation and so few intersections, especially signalized ones. Many freeways also get higher speed limits, which reduces if there are changing conditions, and if there are changing conditions requiring a lower speed, the electronic boards display a lower limit. This is also to help encourage the use of the freeways instead of the local roads. The idea is to ignore the need for a lower speed limit based on changing conditions. An open freeway with almost no traffic allows for much higher flow and speeds than one with bumper to bumper traffic. Weather impacts is also reduced by having systems to tell drivers based on actual formulas (how many people can remember off the top of their heads the coefficient of friction on ice, let alone use that to calculate a safe speed?) when to slow down on these roads.

These roads also could be improved in relation to screening from local roads, cyclists and pedestrians, plus the nearby shops and residents. It adds new sound walls, dense trees and hedges, and makes the big road almost irrelevant. I also minimize the impact by minimizing any homes and businesses that will need to be demolished for this to go forward. Very little would need to be consumed to make this through road network a reality. Most of it would be near the Yellowhead, and the city wants to make it a freeway anyway. Same with Terwillegar Drive and Ray Gibbon Drive, even Manning Drive is going to get several interchanges.

It makes them suitable for the through road classification that Sustainable Safety demands. Let's make the plans to make them work.

Update


I didn't like some of the routing options I had. Especially the river valley route. I wished there was another route, but other routes that would fulfill the task of taking traffic from the other through roads to downtown didn't do the job without severe damage to the neighbourhoods that would occur by splitting them with a new arterial road. They had too many vital cross streets I couldn't close which I would have to do to make them good through roads. I would have to make it something like an elevated freeway, requiring vast amounts of property acquisition, possibly sparking another freeway revolt, or tunneling, which was a bit out of the desired price range and given the problems Boston had with digging a tunnel for a freeway, I didn't want to take the risks, especially the risk of fire and explosions and emissions in the tunnel. None of the options were ideal but I chose what I believed was the best routing I could get. 

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