Movable railing

[Whiskeytown]

This is a bike/pedestrian traffic issue, so kindly forgive me, and refer me to the proper forum if this is not it.

For a pedestrian tunnel, I am designing barriers to slow bicycle traffic. There will be two sets of two offset barriers (called 'chicanes' by one expert here). (The existing barriers are too close to permit bikes with kid or cargo trailers to pass.) I am required to allow the barriers to be swung open (against the wall) to allow a sweeping machine to pass, but be securely locked the rest of the time.

I am considering shop-fabricated railing sections, using sleeves around one upright as hinges, which would, in turn, be welded to plates which would be bolted to the wall. Hinges would allow the railing to be lifted and swung, but not removed. A lock would keep the railing down when not open. The uprights would be in sleeves in the floor when the in the 'closed' position.

Does anyone know of some other solution that works, or at least looks good on paper?

 

[ACtrafficengr]

As a cyclist and PE, I recommend looking for a different solution. Asking cyclists to negotiate a chicane is asking for crashes. Remember that cyclists using paths tend to be the so-called "B" and "C" cyclists - recreational riders and children. They may not have the bike-handling skills to ride through the chicane.

How wide is the tunnel? Is it wide enough to stripe separate lanes for pedestrians and cyclists? Separating the 3 mph traffic from the 15 mph traffic will work better than trying to get the cyclists to slow down.

 

[Whiskeytown]

Thanks for your post.
The tunnel is 96" (8 feet) wide. Chicanes have been in place for decades in this location which has high usage of all levels of cyclists on local trips, as well as pedestrians. There are just no other crossings of the tracks/road here which are safe for most cyclists, let alone pedestrians ,without a multi-mile detour, between a busy commercial district and train station, and a large residential area. The chicanes are located on the ramps about 2/3 of the way down from the top to the bottom. This prevents 20-30 mph head-ons, which would undoubtedly be the result of removing the chicanes all together. Because of a steep grade (12%) many cyclists cannot resist the temptation to speed, and the majority ignore the b&w (regulatory) sign "WALK BIKES". Inexperienced, elderly, and cautious cyclists in general often walk their bikes, however. The existing chicanes are just a little too restrictive to allow trailers, as I mentioned in the first post.

 

[ACtrafficengr]

8' is too narrow for my idea, It would take 12 -15 ft min to work (4 - 5' walkway and 2 4-5' bike lanes). It's probably not an option on this job, but I suggest using a wider box for replacement and future multi-use train tunnels.

Is the tunnel on the grade, or are the chicanes on the approach to the tunnel? I was envisioning chicanes inside the tunnel.

Have you considered using several measures, with the first slightly below cyclist approach speed, and progressively slowing as the tunnel is approached? I wonder if optical speed reduction bars would work. By slowing them as they approach the tunnel, rather than inside it, you can probably come up with a more forgiving design.

 

[Whiskeytown]

A little more description of the tunnel: Approaches are from pedestrian areas and are low-speed. The tunnel entries are ramps that descend at 12%. The ramps are maybe 100' long. About 70' down is a set of chicanes on each ramp. Without some way to slow them, the tendency of cyclists is to speed down the ramp, even though one cannot even see, for example, if another cyclist is doing the same thing from the other end.

We have a workable design for swing-away chincanes, which will be shop fabricated from steel pipe, including a relieved area at the bottom to allow bike trailers to pass more easily without opening it up too much to speeding. Looks like that's what I'll go with, as it is merely a incremental modification on what has been working for years.

 

[sc]

One from left field, why not trial small speed humps. I'ld suggest 100mm high, 500mm wide for the width of the tunnel. Paint/tint (the concrete) them in a bright color to highlight them to pedestrians and cyclists.

You could place them on the top third point of the entry ramp and at the bottom and even inside the tunnel.

Regards
sc

 

[ACtrafficengr]

Speed humps and bikes don't mix well, especially on grades. You don't want cyclists becoming airborn, then trying to land on 1 sq in contact patches.