Metropolitan Traffic Corporation Presents: The Super Street Concept “Two Phase At-Grade System” Copyright 2003 MetTra Corp.
Jul 02, 2015
Metropolitan Traffic CorporationPresents:
The Super Street Concept“Two Phase At-Grade System”
Copyright 2003 MetTra Corp.
Arthur Hale’s CloverleafAASHTO
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Belisario H. Romo’s
The Problem TodayCan we afford to wait?
Today, in our mobility oriented
world, serious congestion and
gridlock is widespread.
The ideal “freeway” mode has
disappeared!
Most freeways are saturated, and
they are indeed NOT free. Ideally
vehicles should ride freely,
without delays from entrance to
exit.
The clogged freeway is
frustrating. Everybody knows is
cramped and slow, but, WHY?.....
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Failed example to solve mobility
The Katy Freeway is congested
more than 11 hours per
weekday, usually in both
directions.
Morning rush hour averages
16 mph.
It is already so slow that
people avoid it!
This is the result of injecting 60
percent of the traffic onto 2
percent of road surface!
At this rate there will be no city left to go to.
Motorists became disenchanted with the freeway
dream.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Analysis…
At rush hours 60
percent of traffic is
force into 2 percent
of freeways road
surface.
The streets, 98% of
road surface, works
at 25% capacity.
There is a traffic
light at the entrance
or exit of a freeway
ramp.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Analysis…
For decades traffic engineers have
transplanted the design philosophies
developed for intercity freeways to the
quite different conditions of the city.
Were new design criteria is essential.
Requirements of high speed design truly
do not apply to urban areas.
Saving time by increasing speed is not
relevant in urban traffic conditions
because average trip distance is
significantly shorter.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Speed 5 Mile Trip 10 Mile Trip
mph (in minutes) (in minutes)
5 60 120
10 30 60
15 20 40
20 15 30
30 10 20
35 51.4 8.6 102.7 17.1
40 7.5 15
45 6.7 13.3
50 6 12
55 5.5 10.9
60 5 10
65 4.6 9.2
70 4.3 8.6
75 4 8
80 4.8 3.8 9.6 7.5
Tra
ve
l Tim
es
Sa
vin
gs
(in m
inu
tes
)
Tra
ve
l Tim
es
Sa
vin
gs
(in m
inu
tes
)
Tra
ve
l Tim
es
Sa
vin
gs
Only…
……
.
Tra
ve
l Tim
es
Sa
vin
gs
On
ly……
….
Increasing average
speeds from 5 mph
to 35 mph on an 5
mile trip would save
51.4 minutes travel
time.
Increasing average
speeds from 35
mph to 80 mph will
reduce travel time
by only 4.8 minutes.
Urban freeways, reduce travel time by insignificant amounts, take decades
to complete, decimates the city and create gridlock by concentrating the
bulk of traffic in less road surface (2%.)
Better returns can be obtained by investing these massive sums in more
advanced designs snatching back the full capacity of the other 98% of
available road surface, the streets network, thus obtaining greater benefit
to cost ratio and increase capacity for the new millennium.
We at Metropolitan Traffic Corporation concluded that in order to achieve
sustainable mobility in urban areas, one goal has to be meet. Solve the
simple street crossing. The basic cell of the network.
We succeeded!Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
In the beginning our main objective was to
improve the highway interchange.
Reducing the number of levels required to
obtain 4 left turns and the 4 trough traffic.
Save land and reduce significantly the cost to
almost 40%
We succeeded!
We manage to produce a design that only
requires 2 levels to obtain all movements
required.
Saves 30% of the land required by the 4
leveled design
And more importantly saves cost and time to
implement it.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
It was only natural to scale the highway
interchange to obtain this concept.
We finally were able to offer a complete
featured interchange within the urban
network of streets.
The City of Phoenix, Az., order us to evaluate
this conceptual design for the Camelback
Road corridor.
Although mechanically efficient the cost
remain a concern when a number of
intersections were considered.
It was at this point, that, in an effort to reduce
the cost we decided to manage the left turns
with traffic lights controls instead of
depressed access ramps.
The result was…………… unexpected! Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
This flattened interchange became the most efficient traffic design ever to
solve the nemesis of traffic: the left turns !
In fact we found that it was feasible to operate with only two phases per
cycle in a same plane. By parallelizing and synchronizing 2 trough traffics,
2 left turns, 2 right turns and 2 pedestrian movements per phase.
Reducing the number of phases at the intersection also allows to operate
the intersection at maximum capacity.
Among other benefits:
Reduces atmospheric emissions and noise. Cleaner air.
Increases capacity by 100% at the intersections.
Coordination and synchronization is greatly improved.
Cycles are shorter delay are reduced to a few seconds.
Pedestrians are safer enjoying full phase to cross.
Can be implemented in record time, is economical, urban and
environmental friendly.
Improves property values. No structures are necessary.
Corridors can be upgrade to work in two phases: The Super Street ! Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.
The technology to avoid gridlock exist. Putting it
together to solve traffic congestion requires
geometrical innovations at the intersections.
Mode separation is required primarily to achieve:Organized traffic operations
Systemic multimodal connections.
More capacity out of the network of city streets.
Efficient detection, control and management.
The mixing of transportation modes is a major contributor in the
generation of gridlock. Mass transit systems, private transportation
and cargo are incompatibles because:
Operative Speed
Turning radius
Required stops
Size
Passenger number
Copyright © 2002 Belisario H. Romo / Mettracorp. All rights reserved.