September 7, 2000
Robert M. Guernsey
RE: Moveable Lane
Dear Mr. Guernsey:
recently contacted us through our Website. This letter will provide you
with some information about our lane separator system.
In February of 1998 we made a proposal to the district
engineer. We had reviewed a study done for the Golden Gate Bridge by
Northwestern University. From that study we determined that moveable wall,
while good for most of the goals being sought, was not capable of
providing fully the desired results. Likewise, our moveable CURB system
is capable of meeting most but not all of the goals.
Our patented moveable conveyor system shifts QWICK KURB®
from one lane to another. Since last we talked to the Bridge Authority, we
have refined the conveyor system, and we use it to effect lane shifts in
roadway construction zones, but it is adaptable to similar shifts such as
desired in your Golden Gate Bridge situation.
Aside from the significant cost differences, the key
distinction between the two systems involves the type of separation
provided. Two-foot wide barrier wall essentially prevents crossovers, with
all the benefits and deficiencies associated with that type of physical
barrier. QWICK KURB® on the other hand presents motorists
with a visual separator, and gives a gentle physical warning of
encroachment, but it requires driver response to prevent a crossover.
Thus, if a motorist had lost his concentration, fallen asleep or had
otherwise not given full attention to driving, curb helps him to make
timely corrective adjustments to avoid colliding with an oncoming vehicle.
However, our QWICK KURB® will not stop a driver who has had a
heart attack, or who been sideswiped and lost control.
|Although crossovers are infrequent on the Golden Gate Bridge, they do occur. Two-foot wide moveable wall can prevent these, while QWICK KURB® can only minimize them. On the other hand QWICK KURB® has a number of advantages over barrier wall. It allows emergency vehicles to cross over, contributes less to sideswipe accidents, needs no wide end-treatments, takes up less lane width etc. There are trade-offs for each system, and only the bridge authority can determine the relative weight to assign for each concern. Exhibit "A” compares advantages, disadvantages and features of both systems.|
That said, the economics of the situation are important. The baffler wall system is very expensive, and while the QWICK KURB® moveable system is much less so, it is not inexpensive. In either case how can you truly analyze cost ‘benefit ratios without the benefit of experience with the two systems? Allow us to suggest (see Exhibit “B”) an interim solution evaluating our system, at least, under field conditions.
understand that the concept of a one-foot wide barrier wall is under
consideration. Intuitively, it would appear to have a different set of
difficulties and benefits. However, we have not attempted to compare a
system of that nature because we have not seen anything like it.
After you have
had some time to review what we are enclosing, our Western Regional
Lane Shifting Conveyor
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