How the Zipper Truck Will Help Your Alex Fraser Bridge Commute

A first of its kind in Western Canada, the Alex Fraser Bridge’s counterflow system operates thanks to a distinctive piece of equipment – the zipper truck – which has arguably dethroned the bridge inspection truck as the ministry’s coolest of all tools.

Unless you’ve experienced a similar moveable barrier counterflow system south of the border – the Golden Gate Bridge in San Francisco, for instance – it may take a bit getting used to. We produced an animated video so drivers know what to expect when crossing the Highway 91 bridge.

We’ve received many good questions about the moveable barrier counterflow system; not surprising, considering it’s so new to Western Canada. We’ve collected the most frequently asked questions (and answers) here.

Why did you choose this system?

We considered other options, such as a signal-operated counterflow system like you see on the George Massey Tunnel and Lions Gate Bridge. Thing is, signal-operated systems do not provide the physical separation between oncoming traffic during counterflow operations. On the other hand, the moveable barrier system allows the median barrier to separate opposing directions of traffic at all times (score for safety!).

What is the counterflow schedule?

The extra lane will be in place for northbound traffic every weekday from 4:30 am to 11:30 am in order to reduce congestion during the morning commute. Outside of these hours, and on weekends, the fourth lane will be in place for southbound traffic.

Did you have to do anything to the bridge to accommodate the increased traffic?

We added a seventh lane to the bridge as part of these improvements by reconfiguring the six previous lanes and removing the shoulders. The lanes were reduced in width from 3.7 metres to 3.55 metres. To help keep travellers safe and traffic flowing efficiently as part of counterflow operations, the speed limit on the bridge was permanently lowered from 90 km/h to 70 km/h.

We also strengthened the bridge to accommodate the additional weight of another lane of traffic, including bridge main span deck repairs, modifications of expansion joints and localized stiffening/strengthening of girders.

Original and new lane configurations of the bridge illustrated.
Previous (above) and current (below) lane configuration

Who drives the zipper trucks?

Our maintenance contractor, Mainroad, uses two trained operators at a time to drive the trucks.

How long would it take the zipper truck to open the 4th lane?

About 20 minutes.

What is the speed of the zipper truck during the barrier transfer operation on the bridge?

Up to 10 km/h while transferring barrier sections on the bridge and up to 30 km/h when it is not zipping.

Why are there two zipper trucks?

The second truck is on standby as a back up, if needed, and when routine maintenance is being performed on one of the trucks.

How does the zipper truck operate during snow conditions?

The maintenance contractor plows the snow ahead of the zipper truck operation.

Could ice get in the track? Is this system used anywhere else where the temperature drops below freezing?

There are several moveable barrier systems in eastern United States that experience cold weather, such as Philadelphia, New York and Washington DC.

Is the truck always attached to the barrier, or does it move away from the bridge when not in use?

When the moveable barrier transfer is done, the zipper truck either parks beneath the Nordel Way overpass or the Cliveden Avenue overpass, depending on the direction of travel.

What about when there’s an incident? Can operators be reactive and move the barrier outside of scheduled counterflow times?

Yes, if required, operators can react to events that warrant a change to the counterflow schedule.

What if someone hits the barrier? How long do repairs take?

Each piece of moveable barrier can be replaced by pulling the interlocking pins out. We ordered additional barriers to have on-hand, just in case. Or, if the moveable barriers require minor straightening after being hit, it’s as simple as running the zipper truck across the length of the barriers.

So, there you have it, folks – a pretty cool tool being used to counter congestion in the Lower Mainland.

It’s worth giving the following related blogs a read, too, especially if you’re a regular commuter in the Greater Vancouver area.

>> How the Lions Gate Bridge Counterflow Works

>> Winter Safety on Alex Fraser and Port Mann Bridge Explained

>> Celebrated Highway Sign Spreads to Fight Fender Bender Congestion

Do you have a question we missed here? Ask us in the comments section below.

Page 1 of 32 comments on “How the Zipper Truck Will Help Your Alex Fraser Bridge Commute”

Leave a Reply to tranbceditor Cancel reply

  1. I assume you still have to add lane indicator lights at the south end of the bridge. It was confusing merging yesterday morning from Nordel Way.
    I also hope you can do something about the north end of the bridge. The 4th lane had to merge back to the right which caused congestion.
    And an on-going issue that seemed even worse yesterday was the exit onto Annacis. That was backed up to the mid-point of the bridge which resulted in people in the right lane (sometimes somewhat recklessly) trying to change into the next lane to the left.
    And while I am on a roll here….can you PLEASE do something about the Queensborogh Bridge? Northbound in the AM backs up from North Fraser Way. Eastbound in the PM is a mess from Byrne road all the way to the bridge…

    • Good afternoon Tod – thanks for your message. We shared your comment with our project manager and here’s what we heard back.

      Regarding your comments about the south end of the Alex Fraser Bridge, field observations were made during the AM peak operations on December 19th and no issues were observed with respect to the Nordel Way NB merge. We do not intend to install any further overhead lane use signal displays at the south end of the AFB for counterflow operations in the NB direction.
      Regarding the north end/fourth lane merge point, field observations were made during AM peak operations on December 19th and no issues were observed with respect to the fourth lane merge at the north end. This issue might have arisen from motorists still familiarizing themselves with the initial traffic pattern changes.
      Regarding the Cliveden exit, field observations were made during the AM peak operations on December 19th and no issues were observed with respect to the Cliveden NB off-ramp queuing. Again, the issue might have arisen with motorists familiarizing themselves with the new traffic patterns.
      We hope that this helps!

  2. Hi there,

    This is great! Thanks for installing. As a daily AF driver, 2 items of feedback to reduce bottleneck:

    1. It would be great to have three lanes northbound BEGIN from 72nd – that merge is a bottleneck
    2. For the PM rush, the merge from 91 onto 99 – the 99 merge lane needs to be much longer to allow traffic to get up to speed before merging. Some plastic dividers (bollards) sould also help in this instance.

  3. The Zipper truck barrier and adding 7th lane helps a lot as it is faster crossing the Alex Fraser bridge today. My travel time has been reduced. Thank you very much for this brilliant solution decongesting the bridge.

  4. Why are there no signs on bridge that
    State Trucks Must Stay in the right lane. I can only imagine how difficult it would be to merge when there is a truck with a trailer in left lane . I see
    Three trucks in row in each lane all the time. Thanks

    • Hi again Sonny!

      Our area manager let us know that commercial vehicles need to have access to the far right and adjacent lane in both directions on the Alex Fraser Bridge to continue on Highway 91 SB farside of the Nordel Interchange and as well Highway 91 NB at the diverge for Highway 91A at the East Channel Bridge.