Comments on: Why Traffic Slows at Tunnel Approaches

By: Smellis

Smellis — Wed, 01 Dec 2010 20:59:37 +0000

Glinda,
I agree that Germans are design oriented and efficient, but i don’t think those “pre-tunnel” joists are meant to prepare drivers for entering a tunnel as much as they are there for structural purposes (to hold the wall that separates the 2 directions of travel).

By: fred_dot_u

fred_dot_u — Sun, 21 Nov 2010 00:18:12 +0000

People who slow while entering an intersection might have had the unpleasant experience of encountering someone else who does not stop at red lights. Four decades ago, my driver’s ed instructor taught us to lift off the pedal and hover over the brake pedal when entering an intersection. Motorcycle safety classes suggest to have one’s hands on the brake and clutch levers at intersections.

If I’m sitting at a red light that turns green, I do not arbitrarily enter the intersection. With a green light, I look left and right before continuing. It’s prevented one crash so far. That’s enough for me to continue the practice.

By: Thomas

Thomas — Sat, 20 Nov 2010 21:56:42 +0000

This is kind of to be expected. What I don’t understand is people who slow down to go through a green light.

By: fred_dot_u

fred_dot_u — Tue, 16 Nov 2010 18:20:17 +0000

I agree, Tony P. So many benefits to such a roadway.

By: Tony P

Tony P — Tue, 16 Nov 2010 16:50:54 +0000

fred: On residential streets, the traffic calming tunnel is practical, cheap, pretty, reduces greenhouse gasses…and it works! It’s called a tree canopy.

By: fred_dot_u

fred_dot_u — Sun, 14 Nov 2010 03:27:47 +0000

JJM P.E. appears to have the answer for slowing down drivers in residential areas that have had the roadways expanded and “improved” to the point where speeds are excessive for any other uses in a safe manner.

Let’s put up tunnel walls and tops and slow those cars down!

yeah, not practical, but even a narrower roadway would probably help in that respect.

By: JJM P.E.

JJM P.E. — Sat, 13 Nov 2010 00:50:50 +0000

Given that the same thing happens at the Kosciusko Bridge near Albany, NY (a through-arch) I suspect that the sense of confinement has as much to do with it as going under a mountain or river. Drivers feel that they have less room for error, and slow down to compensate.

It’s even been noted next to concrete barriers and other obstructions.

I suggest maintaining shoulder width, or even making them wider, as well as tapering the entrance, rather than abruptly narrowing the roadside.

By: Scott

Scott — Fri, 12 Nov 2010 01:35:50 +0000

Yes, drivers should slow down when approaching a tunnel that they cannot see into.

They should not be braking, however. Drivers should look ahead, notice they are approaching the tunnel, and decelerate gradually rather than hit the brakes.

I think that better driver education would help. Too many people tailgate as well as jam on the brakes when they should simply decelerate more gradually.

By: Glinda

Glinda — Thu, 11 Nov 2010 18:10:51 +0000

They slow down to adjust to the darker light. A “pre tunnel” consisting of a series of arches that reduce direct sunlight could ameliorate the problem. Example: go to Google Maps and type
51.230366,6.738746

By: Betty Barcode

Betty Barcode — Thu, 11 Nov 2010 01:09:22 +0000

People slow down for all the right reasons, such as the recognition that an accident in a tunnel would be deadlier than one on an ordinary highway, where there are no walls to smash into. Also, the tunnel is presumably darker, and if you can’t see what’s ahead, it is appropriate to slow down. Mulad is right; why do we want to condition people out of good behavior?