🚀 go-pugleaf

Scott M. Kozel wrote in message <36C78AF7.7CCD@richmond.infi.net>...
>"Douglas A. Willinger" <dougwill@idt.net> wrote:
>>
>> Scott M. Kozel wrote in message <36C650BA.2A2B@richmond.infi.net>...
>> >"Douglas A. Willinger" <dougwill@idt.net> wrote:
>> >
>> >Yes, but traffic volumes on the Beltway have tripled since then.  It now
>> >carries volumes ranging from 190,000 to 225,000 vehicles per day.
>>
>> Has not the Beltway also been widened during this time, though
admittingly
>> not being tripled in capacity?
>
>Of the 64 miles, 50 miles was 6 lanes initially, and 14 miles was 4
>lanes.  Now all of the Beltway has 8 lanes except for 4 miles of 6-lane.
>
>I've got the Beltway history here:
>"Capital Beltway (I-495 and I-95)" -
>http://www.richmond.infi.net/~kozelsm/CapitalBeltway.html
>
>> >Hence, a 55 to 60 mph speed limit today is appropriate.
>>
>> 55 or 60 mph may be a perfectly appropriate speed upon the Beltway, even
in
>> the far left hand lane under certain traffic conditions; indeed the
>> appropriate speed may be even lower, again, due to due to traffic/weather
>> conditions.   If for instance I enter the Beltway eastbound from Rt. 355
>> south at 4:30 PM on a weekday (an especially dreadful ramp insofar that
one
>> can not see the traffic conditions upon the eastbound Beltway before
being
>> committed to entering it) and encounter heavy traffic flowing at say 35
mph,
>> than 35 mph is about the speed limit for those conditions to hold to.
>
>Certainly during peak hours, the speeds can be limited to that or even
>lower, by traffic congestion.
>
>> However, is placing a set speed limit lower than what is appropriate
under
>> better conditions involving the average car and driver, and to enforce it
>> when such faster speeds are appropriate for such, and not involving
>> tailgating, weaving, or even a speed differential of more than 5-10 mph
an
>> appropriate policy? [...]
>
>But how would a speed limit system be structured to provide one limit
>during peak hours (ex.: 55mph) another during off-peak hours (ex.:
>65mph) and another at times of the lightest traffic (ex.: 70mph)?


Conceivably this could be accomplished in much the manner numerous HOV lanes
are already so regulated.

>I agree, with 8 lanes, the Beltway is wide open during the wee hours of
>the morning; and that 70 or higher seems safe.

Indeed, this is the case even quite often during the middle of the day, from
my observations living in Takoma Park and Bethesda, Maryland, and using the
northern portion of the Beltway fairly regularly.

> But I'm not sure how
>feasible a time-based speed limit system would be.

Possibly no less feasible than time based HOV restrictions- especially
considering they would apply to the entire roadway (insofar as a comparison
with nonbarriar separated HOV from a standpoint of enforcement).

Time based speed limits are but one possibility.  A better one -- more
directly relevant -- might be DENSITY based speed limits, with the limits
higher with lower densities, and via versa.  A means for continuous data
input already exists with the numerous imbedded sensor (counting) units,
usable for recording the amount, spacing and speeds of traffic, and be a
more meaningful variable speed limit than a simple time based variable speed
limit.  (However, another thing that might be explored are speed limits that
vary upon the position of the sun in instances where the position of the sun
somewhat blinds drivers heading in a certain direction).

>> Of course, one must also ask, if it also wise policy to continually
ignore
>> the most needed roads directly relevant to why the Beltway is so
overloaded,
>> namely the utter lack of a comprehensive highway network for Washington,
>> D.C.?
>
>How true, Doug! :-)

Alas, the poor state of Washington, D.C.'s road network remains a largely
neglected issue (along with many other issues regarding the unfortunately
poor state of affairs of the District).

Indeed, the unbuilt North Central Freeway, which in its 1962 and later
permutations as a consolidated "Y" route (the upper right or north-eastern
portion of the "Y" as the unbuilt I-95 North East Freeway), and which would
have been been the I-70S (I-270) inside the Beltway extension via the upper
left or north western portion of the "Y" (which ran via the B&O railroad
corridor in the 1966-71 routings), was once proposed with a 70 mph design
speed, north of the proposed junction with the I-95 North East Freeway.

Douglas A. Willinger
Takoma Park Highway Design Studio