Introduction
A concept
is suggested in the article for an integrated infrastructure facility to permit
the use of road space by all passenger and goods modes through lateral and
vertical segregation of traffic. The concept considers the provision of a
pedestrian crossing facility at surface level and a segregated and protected
cycle track. The concept also provides a 24 x 7 movement of trucks through
urban areas.
Introduction
Urban
Areas (UA) develop around a concentration of economic activities or transport
corridors – rail and road – and also on the sides of the rivers. They grow in
to towns, cities, and; metropolitan cities and regions & others. So do the
transport network and its complexity. The complexity arises for two reasons.
One, the UA orientation changes from mono centric (CBD Central Business
District) to poly centric (Multiple Business Districts) increasing the
complexity of movement (trips – people and goods). Of course, poly centricity
aids in reducing the average trip lengths. Two, the inter mixing of urban and
regional traffic as UA growth is around a regional transport corridor. The later impact is different on the two
networks – rail and road – due to the nature of the traffic the two systems
handle.
Rail,
for example, segregates regional long distance traffic and satellite town
traffic (generated due to growth of an UA) through introduction of Sub-Urban
rail services on the same or capacity augmented network. Urban traffic on the
rail based – Metro / LRT (Light Rail Transit) – systems are on a different
network and normally use the space above, on or under the road network. Such
systems are mainly provided in large UAs to reduce the pressure on road based
system. The last mile connectivity for passengers is a road based system.
A road based system not only has to segregate
urban and regional traffic but also different modes to enhance the safety and
efficiency of each of them to the extent possible within the ROW (Right of Way).
The
modes of transport used in UAs in India can be classified as:
1. Pedestrians
2. NMV – Non-motorized
Vehicles ( Cycles, Cycle Rickshaws, Pull/Push Hand Carts, Horse and other
Animal Carts)
3. LMV – Light Motor Vehicles
( Cars, Vans, Motor Cycles, Auto Rickshaws, Light Goods Carriers)
4. HMV – Heavy Motor Vehicles
( Buses and Trucks)
There
are no restrictions, generally, on cycle movement. The facilities for their
safe movement, in most and all sizes of UAs, are abysmally low though. Even
where present, for instance, cycle tracks are not continuous and form a
corridor for their effective use. However, the movement of the rest of NMVs is
restricted, especially in larger UAs, to certain pockets and is prohibited on
arterial roads while no restrictions are in place in smaller UAs. Trucks in
some large UAs are restricted in certain specified hours in the daylight period
or whole of it to manage the traffic during the referred time.
These
restrictions and negligent supply of infrastructure for pedestrians and cyclists
has not resulted in lasting solutions for urban traffic in large UAs. It must
be remembered that walking and cycling were the predominant modes not only in
smaller UAs but also in mid sized and large UAs in which the bus was the third
mode prior to the easy availability of cars. All the three modes of transport
are environment friendly, energy efficient and are not capacity guzzlers of
urban road space. The cars, of course, cannot be dispensed with and in fact
restrictions need to be in place for their use as well as ownership.
So,
there are a number of modes competing for the same road space. Thus far, over
several decades with increase in use of motorized vehicles, especially cars,
the allocation of road space is tilted towards it neglecting other modes
including buses. The supply of buses has not kept pace with the demand and
resulted in further increase in car usage.
The lessons learnt while planning safer facilities for the movement of
cars, or in general for motorized vehicles, due to their extensive usage, over
the decades should be used for integrating the infrastructure for all modes,
including that for pedestrians and cyclists, for their safe and efficient cohabitation
in a given road space.
A concept is suggested here for an integrated infrastructure facility to
permit the use of space by all passenger and goods modes through lateral and
vertical segregation of traffic.
Concerns and Issues
The
restrictions on NMV vehicles other than cycles may continue as prevailing
currently as they are labour intensive and are not appropriate for long
distance and arterial road movement. The modes having restrictions which have
impact on the environment and economy are pedestrians, cycles (NMV) and trucks
(HMV). The concerns and issues of movement of these modes are detailed later.
These should be considered as constraints or requirements and need to be
addressed appropriately while allocating road space to different modes. Bus
movement has no restrictions currently; however, their movement and associated
activities are not to the desired level of safety requiring allocation of an
appropriate space for buses which enhances safety for all modes in the system.
The
objective of the concept is for Optimal Allocation of Road Space (OARS) for
safe and efficient movement of all modes appropriate for arterial roads subject
to satisfying the constraints to the extent possible.
Pedestrians
Every
vehicular trip starts and ends with a walk either along the road and / or
across it. In addition to this, walk is the only mode of travel for many, even
in larger UAs, especially those who need to move short comparable distances to
those observed in smaller UAs.
Their
movement is constrained by the absence or availability of less space on
sidewalks (footpaths) due to encroachment by vendors. There is an opinion that
presence of vendors increases the safety of pedestrians on the roadway.
In
which case, it would be ideal for the design width of sidewalks to account for
the presence of vendors.
The
pedestrian movement across the road is catered to by three methods and the
fourth is adopted by the pedestrians:
1. On surface (ground level) –
Zebra Crossings at select locations with or without signal control.
2. Elevated (above ground
level) – Foot over Bridges (FOB) above the road at height over 5.5m.
3. Depressed (below ground
level) – Underpass below the road at depth below 2m
4. Jaywalking – Pedestrians cross
a road on surface wherever they like to do so. This is undertaken for a variety
of reasons in all regions.
Pedestrians
resist using defined paths for crossing, for example, at a zebra crossing, at
signalized intersection due to the absence of an all red phase for motor
vehicles requiring pedestrians to identify gaps between greens and cross.
Pedestrians
also resist using elevated or depressed facilities to avoid going up or down
the stairs / ramps in addition to the distance they need to walk to access the
facility.
Therefore,
efforts are necessary to identify paths which are safe not only for pedestrians
but also to vehicles including special vehicles used by people with
disabilities. The following should be considered for allocation of road space
for pedestrians and special vehicles.
1.
Cross
pedestrian movement is maintained at surface level to the extent possible.
2.
Avoid
cross pedestrian facilities which need going up or down ramps / stairs.
3.
Minimize
pedestrian vehicular conflict.
4.
Minimize
waiting time for crossing pedestrians.
5.
Sufficient
width on sidewalks for pedestrians over and above the space required for
vendors and the row of buyers in front of stalls.
6.
Width
of sidewalks should be sufficient to accommodate special vehicles.
Cycles
Vehicular
traffic of buses (in whichever UA the service was available) and cycles were
together the predominant modes of travel prior to the increasing availability
of fuel efficient motor cycles (scooters) over a period of time. This initially
and later the availability of cars (both being motorized vehicles) had a
significant negative impact on the usage of cycles being a manually operated
vehicle. Additionally, the limitations in improving the bus services and their
availability resulted in increasing usage of personal motorized vehicles further
negatively impacting the usage of cycles. Capacity augmentation, if any, was
quickly filled by motorized vehicles increasing the risks and affecting the
safe movement of cycles. Even the experimental cycle tracks, in certain UAs,
were encroached by motor cycles. This resulted in pushing cyclists to main
carriageway. Additionally even cyclists
adopted jay-cycling similar to jaywalking. Jay-cycling is also due to the
absence of continuous cycle tracks. Therefore cyclists with increased risk necessarily
have to share space with motorized vehicles.
Also,
people with disabilities use special vehicles. The special vehicles could be
wheel chairs, non-motorized trikes or those which are not high speed motorized
vehicles that eliminate manual operation and facilitate easy movement of such
people with minimal stress. The access to these vehicles in most UAs is very
limited or in fact non- existent. These vehicles may share the same space which
cycles use, as the conflict impact, if any, would not be as severe as it would
be with high speed motorized vehicles.
It
is essential cyclists and people with disabilities are given due share of road
space for their safe movement. The space allocation should also encourage more
people to use cycles considering its safety aspects. The following should be
considered for effectively encouraging the usage of cycles.
1.
Cycle
tracks should be continuous to form corridors.
2.
Minimize
conflict with motorized vehicles at intersections.
3.
Segregate
cycle traffic from motorized vehicles.
4.
Cycle
tracks to be motor cycle encroachment free.
5.
Width
sufficient to encourage
a.
Increased
use of cycles
b.
And
also by people with disabilities with their special vehicles.
Buses
Bus
is the predominant mode of mass transport systems (MTS) in most UAs. There are
no lane restrictions for their movement. Bus lanes delineated in some UAs
proved unsuccessful. The bus stops are on the outer edges (curb side) of the
road. The movement of buses from an outer edge lane to inner lanes is a
hindrance to the safe movement of other modes. This to some extent is addressed
by BRTS (Bus Rapid Transit Systems) which being a segregated facility operating
on protected lanes. Recent efforts in many UAs are in terms of developing BRTS
to enhance the efficacy of MTS operated bus mode. However, the pedestrian
access to BRTS in the middle on surface as provided in some cases is a safety
concern.
The
movement of buses and associated activities (boarding / alighting and access to
bus stops on the sides or in the centre) of bus services either conventional or
BRTS should enhance the efficiency and safety of transport system by
considering the following:
1.
Minimize
conflict of passengers accessing bus stops with movement of other modes.
2.
Minimize
conflict of movement of buses and other modes.
3.
Segregated
bus lanes (elevated or centre of the road on surface).
Trucks
Truck
movement over a period of time, during which the UAs grow in size, is diverted
to the periphery – bypasses or ring roads (RRs) – developed for the purpose. This
diversion is primarily to reduce congestion in the CBD of the UA by segregating
urban traffic and through goods traffic. However, ribbon development occurs
along RRs resulting in further growth of UA requiring multiple RRs for an UA. This
increases the distance the trucks need to move across an UA. There is a limit
to the RR’s spatial separation from the centre of the UA beyond which an RR
ceases to be a bypass. When this limit is reached or felt a need for another RR
and till it is built, urban traffic is managed by banning the movement of
trucks. The ban is enforced initially in certain periods during daytime hours
stretching in some UAs to the whole of daytime period and in to the night hours till urban traffic tapers down. The window for goods movement cannot be reduced
any further considering the volume of traffic waiting at the periphery of the
UA to move across. The result, during the window for goods movement, is
congestion levels similar to those observed in daytime hours, some years ago,
are back. The reason for congestion is the combined effect of truck movement
and stretching of urban traffic movement well past midnight with increasing
number of economic activities occurring during the night hours. A high volume
of truck movement during a small window in the night hours has severe impacts
on the air quality in the UAs resulting in highly polluted atmosphere in the
early morning hours affecting morning walkers.
The
contiguous development of UAs, especially in the form of a Mother City and
satellite towns is impacting the movement of trucks further. Regional RRs are
being considered to ease the movement of trucks or for their continuous
movement in all times of the day. This may initially reduce the pressure on
urban road network but likely to resurface and have significant impact
especially on the network of Mother City as truck terminals, if any, are
developed are at its periphery.
Therefore
it is prudent to allocate road space for movement of trucks on urban road
network considering the following:
1.
Trucks
to move on shorter feasible urban arterials.
2.
Trucks
should be able to move 24 x 7 on allotted space.
3.
Minimize
conflict with other modes.
4.
Segregated
facility for trucks movement.
Capacity Augmentation
Most
urban arterials have 2 x 2 to 2 x 4 lane configuration on surface. Traffic on
most of these roads has reached or nearing capacity. And, roads have reached
their limits for further expansion due to limitations of ROW (Right of Way). Land
acquisition for capacity augmentation is very cumbersome, expensive and is
limited especially in UAs as it is required for other uses as well. It is not
easy in rural areas, adjoining larger UAs, either for development of
alternative corridors. The congestion levels in most urban arterials suggest
that a substantial level of increase in the capacity is essential to meet the
norms of desired LOS (Level of Service) for the current traffic volumes. Thus,
additional capacity would be required to address the traffic generated in
future. So, is a dead end in sight?
No.
The
current state of the road based transport system suggests the need for
rationalization of traffic demand and optimal use of surface along with the space
above and below it. The demand rationalization can be achieved by enhancing the
capacity for environment friendly and capacity efficient modes.
1.
It
has been reported that additional capacity created fills up by additional traffic
and not
necessarily it reduces the congestion. This has been generally in the context
of cars. If this is true of cars then it should also be the same for other
modes.
2.
It
has also been reported that reallocation of road space for environment friendly modes does not necessarily increase traffic woes but in fact reduces them with people making rational mode
choice.
3.
Different
types of elevated roads have been conceptualized and built in some UAs to ease
the congestion on certain stretches of the urban road network. The space below
most elevated roads or flyovers at intersections has not been optimally
utilized or remained undeveloped. There are some examples where the space below has been put to use for the development of shops or warehouses and even recreational areas. Some of the elevated roads, of course, are over drains
or canals which perhaps cannot be used for any other purpose.
The
concept being suggested here is a combination of capacity augmentation and
reallocation of modes to spaces – below, on and above the surface – and use of
space below elevated structures for transport purposes for realizing the stated
objective.
Conceptual Mode Segregation
A
typical mid-block section between two intersections could have an arrangement
as shown here.
Pedestrian Movement
The
width of foot path should be sufficient to serve the volume of pedestrians and
special vehicles moving along the road in accordance with the requirements for
their safe and efficient movement.
Cross
pedestrian traffic can move on the surface between two service roads on either
side using the connecting dark green stretch. Pedestrian conflict with
vehicular traffic is eliminated on the main carriageway by semi-elevating (2.5m)
the path for LMV traffic on both sides of the road. A limited pedestrian - vehicular
conflict will occur on service roads and with turning cycles which would
negotiate the rotary to access the service roads and adjoining built-up area.
Cycle Movement
Cycles
can move in the centre of the road using the dark green strip which runs along
the road. In fact the cycle track is in the position occupied by median on a
conventional road. Straight moving cycles can use the underpass along the
stretch in light green colour. This will minimize the cycle-pedestrian conflict
at the rotary location. Cycle track in the middle serves the purpose of a
median segregating the LMV traffic moving in opposite directions. Cycle track
would be protected from LMV traffic by the piers which will support the
elevated road above along with other planned barriers. The elevated road also
provides pedestrians and cyclists with a covered facility protecting them from
sun and rain.
As
the cycle tracks can be accessed from service roads at surface level these
facilities would be accessible to people with visible or invisible disabilities
using special vehicles. The slope for the ramps suggested for straight moving cycles
could be designed to suit special vehicles. Alternatively, straight moving
special vehicles could be permitted to negotiate the rotary for the purpose as
an exception.
LMV Movement
LMV
movement would be along the lanes adjacent to service roads on either side of
the road. LMV lane would be semi-elevated in the middle to permit the passage
of pedestrians and cyclists safely to the other side or to access the cycle
tracks in the middle. Access between service road and LMV lane would be at the
locations before and after section of road shown. The option of depressing the
LMV lane by 5.5m to accommodate emergency vehicles and other large vehicles, if
any, that are likely to move was discarded considering that it would be
uneconomical compared to elevating. This
would also have not permitted the economical use (described later) of space
below the pedestrian path and adjacent to the cycle underpass.
HMV Movement
Elevated
road may have a lane configuration of 2 x 2 or 2 x 3 depending on which of the two
HMVs will move on it. That is, if the
route is to cater to only buses or only trucks it could have a 2 x 2 facility.
And if both modes are required to move on the route, it could be any of the
configurations depending on the capacity requirement.
However,
in a 2 x 3 facility restrictions may be such that at least one lane in each
direction is available for trucks to move during the day and similarly for
buses in the night hours.
Elevated
roads are suggested for eliminating any time restrictions for movement of
trucks through an UA on shorter (both in terms of distance and time) roads as
compared to the peripheral roads. This will have a positive impact on the
economy eliminating retention of trucks at UA entry points and reducing the
travel time to move across it.
Currently
BRT systems are being considered in most UAs. These are mostly on surface and
have controlled movement at intersection through priority signals. Even this
constraint can be eliminated by the operation of an elevated BRTS. The bus
stops for the system could be modeled on the stations for metro service. The
pedestrian access to BRTS will be a safe facility. The space below pedestrian /
cycle crossing facility on surface could be used for parking of personal and
rentable cycles. This will address the last mile connectivity issues which are
present with most MTSs.
Alternatively
the light green strip in the middle can be designed to accommodate BRT
operations as well as for straight moving cycles. This will provide BRT
passengers with easy access to parked cycles. If not possible due to
limitations of ROW straight moving cycles can use the same strip which turning
cycles use. Elevated road thus can be used only for truck movement.
Access
to the elevated road could be implemented very effectively as it will cater to
only HMVs which have definite entry and exit points.
Trucks
for instance, originate or terminate at truck terminals, or enter and exit at
UA boundaries where they may also be stopped from entering to manage traffic
congestion within the UA. So access to elevated road for trucks could be at
these locations only.
On
similar lines buses could have access to elevated road only from or to bus
terminals and depots. Such access
control will enhance the efficiency of BRTS and it may match the service of a
metro system and perhaps providing an optimal MTS.
Emergency
services (ambulance, police and fire engines) which are required to address any
issue requiring such services on elevated road could access it by the access
facilities developed for HMVs. Additional access facilities for emergency
vehicles may be built, if feasible, especially at locations from where they
already operate.
Circulation
Here
an alternate pattern of circulation for pedestrians and cycles in the mid block
is suggested.
A
rotary arrangement at a 4-way intersection permits uninterrupted vehicular
movement. The space enveloped by LMV rotary and surface could be used for Cycle
parking and pedestrian crossing facilities and also for shops to enhance the
security in this space.
Thus
the four categories of transport modes – pedestrians, cycles (NMV), LMV (cars,
motor cycles and others) and HMV (buses and trucks) – are segregated laterally
and vertically by assigning an appropriate level in the road space for their
safe and efficient movement minimizing any conflict between them.
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