The steady invasion of new cars into cities across the globe have caused crossing a street is in town no more an easy undertaking. People get lesser chance to succeed in pedestrian crossing on busy hours of working days. Crossing a street in traffic lights, causing a long to traffic built up on roads and street in many cities around the world with time.
To get rid of this problem, and prevent casualties to happen on road's and street’s surfaces, an overhead pedestrian crossing, or underpass, must been called for.
An Overhead Pedestrian Crossing, shorten OPC, is a bridge, or collection of bridges, ± 5 meter above the street’s surface for pedestrians to cross, so diverse vehicles may pass separately underneath; while an underpass is a passageway built about ± 2.5 meter under a road's or a street’s surface for pedestrians to cross, so a variety of vehicles may pass on the surface separately.
An OPC may be established anywhere one like in a city, but an underpass must be built in carefully chosen location to get rid of crime. This is the reason why an OPC is preferable than an underpass. There are two categories of OPC to be welcomed by most city dwellers: a Straight Overhead Pedestrian Crossing, shorten SOPC as seen in Figure-Ia, and an Integrated Overhead Pedestrian Crossing, shorten IOPC, as shown in Figure-Ib.
Figure-I
SOPC is a straight overhead bridge to connect two sides of a street, while an IOPC is a collection of interlink overhead bridges or integrated overhead bridges, to encircle a roundabout at motorway junctions.
An IOPC not necessarily form a perfect circle like the one shown by bird’s-eye view Figure-Ib; but it can be be a loop or any form depends on existing environment of the motorway interchange. In this way a culture for crossing a street can be introduced: first, pedestrians will be taken by elevators from a street side to SOPC, or IOPC; then they are allowed to walk some or the full length of integrated overhead bridges, finally elevators bring them back to the surface of other side of street.
To bring pedestrians from street’s surface up to a SOPC or an IOPC, and the other way round, a mechanical device will be introduced, called "Pedestrian Elevator", shorten PE. The latter will replace stairways of all kind, so no human muscular power is required by pedestrian to get from one street’s surface to SOPC or IOPC, and the other way round on the other street’s surface, because PE is driven by a brake induction motor fed from utility.
The PCC (Pedestrian Carrying Capacity) of this PE depends on its size especially the floor area; the larger the latter the more pedestrian it can carry one way up, or the other way round.
Both SOPC and IOPC are built from of steel channels involving C-Channel, or H-Channel, steel pipe, steel plate, etc. Some can be established from reinforced concrete, especially overhead bridges and their supports while the rest out of steel for economy.
Two elevator design has been foreseen, that is to say: a Peripherally Braced PE, shorten PBPE, and a Centrally Braced PE, shorten CBPE, as seen in Figure-II.
Figure-II
A PBPE is a square or circular like cage made of steel structure for a peripheral support, where a cabin is made to ascend or descend inside. Unlike a lift in a highrise building, PBPE does not require any suspension cables along with its accessories. Instead, it has a platform for base equipped with four Lifting Devices, shorten LD, backed by a simple technology: 1. Bolt-Nut with Bevel Gear, or 2. Rack-Pinion with Bevel Gear and Worm Gear; driven by a brake induction motor.
The four LD will move PE cabin up in unison, or the other way round also in unison, synchronously driven by a mechanical system inside platform’s compartment right under cabin’s floor. Cabin cannot sink by action of gravity, i.e. its own weight and pedestrians inside, unless be driven by its brake induction motor.
Electricity comes from utility by power cable and enter PBPE’s panel, then by way of power wiring and a roller it will get to cabin panel. Alternatively, electricity may be sent to cabin panel by way of three insulated copper rail to be collected by carbon brushes. Should utility fails, an emergency power supply will immediately take over.
With advent solar panel and wind generator, energies harnessed from the sun and wind can be used to run PBPE after been converted to electricity. Electricity is use to run brake induction motor, electronic control, and lighting.
A Programmable Logic Controller (PLC) will be implemented to interface pedestrian with PE’s electro-mechanical system, along with limit switches, control wiring, and push buttons.
A CBPE is similar with PBPE, but built to support from its center, where a square or round cabin is made to ascend or descend from outside. The central support is in fact a column made of steel construction or reinforced concrete. Like PBPE, a CBPE also has a platform for cabin base equipped with four Lifting Devices backed by a simple technology: 1. Bolt-Nut with Bevel Gear, or 2. Rack-Pinion with Bevel Gear and Worm Gear; driven by brake induction motor. The four LDs work in unison to move PE up, or the other way round in unison, synchronously driven by mechanical system in the platform’s compartment right under the cabin floor. Like PBPE, cabin cannot sink by action of gravity, unless be driven by its brake induction motor.
To take a pedestrian up from a street’s surface starts with PE descend until its floor levels with the street surface. By the press of Open Button (OB) from outside the cabin, the door will open and pedestrian can get in. With the press of Close Button (CB) inside cabin, PE will ascend and will stop after it hits the upper limit switch. OB then be pressed in the cabin and the door will open, pedestrians can leave cabin into SOPC or IOPC, finish.
To bring a pedestrian down from SOPC or IOPC back to street’s surface, begins with PE ascend until its floor level with each bridge floor. With the press of OB from outside, cabin door will open and pedestrian can get in. CB then be pressed from inside, cabin will descend and stops after it hits the lower limit switch. OB then be pressed from inside, pedestrians can leave cabin to street surface, finish.
A dissimilar tune of music will be heard during ascend and descend so people around the neighborhood will aware of PE activities.
SOPC will be built on busy streets, while IOPC is established around busy motorway junctions, so pedestrians may be completely separated from vehicles. With a complete separation, vehicles average speed on the street may be increased to its economic value; and this will lead to the saving of fuel consumption, reduce air pollution, shorten travel time, and restore street order. The latter cannot be achieved by the modification of street order per se (Software), but must be in synergy with SOPC or IOPC (Hardware) as well. This is the "S-H solution" to a city traffic problem.
It is necessary to bring punishment to someone who intentionally cross streets where SOPC or IOPC already in operatioan for a municipal disobedient. The legal action is obvious, because he/she who deliberately cross street will provoke drivers to change speed abruptly against its economic value, causing fuel consumption to soar, air pollution to worsen or deteriorate driver’s carbon footprint to the environment, broke order, and lost of precious time.
With advent of SOPC and IOPC, pay crossing may be introduced. The fee is needed to cover the costs of operation and maintenance, should local government decline to subsidize the newly introduced urban infrastructure financially. With a catchword “everyone can pay across”, whoever is found to have no money honestly, will be granted "money in cash", from the management or a philanthropist to get across.
SOPC, or IOPC, will not earn money solely from crossing fee. There are many ways for the new public infrasructure to find income to cover its spending, and this is much depends on management at the helm. With SOPC or IOPC in cities across the globe, elderly and disabled have the benefit of easy and save to cross roads and streets; so do women and children. Similar SOPC and IOPC can also be develop for motorbike and passenger car to divert them to a nearby side roads or side streets, should long time congestion occurs in motorway or toll road.
The Innovative Overhead Pedestrian Crossing has been filed in Patent Office of The Republic of Indonesia, in Jakarta, on April 14, 2004 under the title: “Penyeberangan Jalan-Raya”.
