Questions and Answers Sky-Cycle-Ways, Elevated bike lanes

 

Q. Are the bikes attached somehow to the skyway ?

A. No they are normal bicycles.

Q. I thought by all this talk of monorails that they where hanging down somehow.

A. No all the talk about monorails is about how to introduce a new transportation network with out interrupting the current ones or taking space away from them. The only space left to create a new transportation network is above you or below you. If you elevate then you need to follow the monorail thinking.

Q. Are you really serious about being faster than cars ?

A. With the important proviso that you look within a limited distance in a congested city then yes. Bike messengers are already quicker than taxis in many city centers. Yet bike messengers only have the advantage of moving to the front of the traffic light queue. Imagine how much faster they would if they had no lights. The skyway system eliminates junctions and so speeds the cyclist though the urban environment.

Q. Do really want to clear the streets of cars.

A. No absolutely not at all. The whole reason for elevating the skyways is to make sure they don't block the roads. The skyways are about reducing congestion, 48% of trips in America are less than 3 miles. By moving people up into the air then more space is created on roads for people with longer distance journeys. Unlike many alternative proposals ( light rail, bus only lanes ) but like elevated rails and monorails skyways don't take space away from motorists. Most engines produce most of there worst pollution early in the car journey before the engine has time to heat up. By removing some of the short journeys then some of the worst effects of vehicular

Q. Won't skyways visually interfere with our upper visual amenity ?

A. No - Firstly the visual amenity of most of America about 17ft off the ground is quite poor to being with. Monorails lead in having minimal rail to obstruct the sky. Single lane skyways have the advantage of being quite thin and so not obstructing much light. Elevated rail ( such as the Chicago loop ) have the disadvantage of obstructing most of the light down to the street level. Skyways can absorb some of the telephone infrastructure and so clean up the visual amenity in some locations.

Q. Are you really think each street in the US will have it's skyway

A. NO, Skyways are like freeways, long stretches of uninterrupted arterial which are fed by a network of streets. The local street system feeds the skyway. If enough of the network exists you will do 90% of your journey in the skyway system. The skyway network its self would be at most 10% of the street network. Like mass transit this requires some portion of your journey at street level to the nearest station. This journey would be by bike so shortening your time to station.

Q Surely Cars will hit the legs of the skyway knocking the whole thing down ?

A. The legs Monorails have been built for years with this possibility in mind, skyways are no different. Monorails and skyways can be built away from streets where possible. Being so light, quiet and vibration free it is possible for skyways to be suspended from builds where possible.s

Q. What about escape in case of fire ? Surely the stations are too far apart for safety.

A. Each leg would be equipped with a ladder and escape mechanism in case of fire. A constant monitor would be kept on all aspects of the monorail. This is safer than some monorails where sister train has to be used or failing that a fire truck. The ladder would be an exit only mechanism.

Q. What happens if someone decides to watch a parade by going up on to the skyway. Won't the weight of people crush the skyway ?

A. The floor of the skyway is quite narrow ( see some of the cross sections ). This limits the number of people who could possibly stand on the skyway, Pedestrian bridges and walk ways are quite a familiar design, and note that pedestrians are banded from the skyway as they are from freeways. The design of the skyway will be to support the minimal number of people, and so use the minimal amount of structure to achieve it. The skyway will generally be built to the maximum number of (banned ) pedestrians and so provide a large margin of safety for the less dense cyclists.

Q. What about motorbikes on the system won't they cause problems ?

A. On the skyway system motorbikes and scooters are banned. The entry barrier mechanism has alarms for weight and carbon monoxide. Security cameras alert mobile security guards who can block junctions until the offender is escorted off the network.

Q. What about electrically assisted bikes ?

A. Electric bikes with not much more power than a normal bike would be permitted, the important thing is to keep the speed of the network about constant. Vehicles which are too fast or too slow should not be permitted. Very fast vehicles will cause accidents, non motorized bikes should not be a problem. Slow vehicles would increase the general travel time.

Q. What about roller bladers and skateboards ?

A. If they can move at the same speeds as the bikes then no problem, if they tend to be drastically slower or faster then they should not be permitted.

Q. Skyways will they be really really expensive ?

A. Compared to what ? Assuming that doing nothing about congestion increasing the average journey time from 1 hour to an hour and 30 minutes of being stuck in traffic is free then yes skyways are expensive. Buses aren't cheap ( about $250,000 per LPG bus plus more for the driver), they don't compete with cars for convenience. Buses are also subject to the same kinds of slow downs as a city generally congests. Bus only lanes take space from car lanes and are unpopular. Light rail either shares the road ( so suffering from congestion) or requires new space which has to come from somewhere. Monorails and Elevated Personal Rapid Transit don't get stuck in traffic. Monorails,light rail and segregated buses suffer from the slowdown by stopping at regular intervals so reducing the door to door speed. Personal Rapid Transit does offer the potential for faster door to door systems but is as yet 'an untired' technology. Skyways where derived from looking at ways of making PRT cheaper, by reducing the weight of the carriage compared to the passengers then the overall weight and so cost and number of supports.

Monorail costs between $68million( Bombardier MVI Maglev) and $6.52 million ( Carr West, England ) per mile. The Skytran system estimates costs near $1 million per mile for a Maglev system. The objective of a skyway would be to significantly undercut this cost. Remember we don't have to maintain the vehicles, the only moving parts are common elevators and escalators. Effectively the installation of a skyway is little more than digging a hole for the foundations, then using a crane, to install the legs and then topping the whole thing off with a factory built 'bridge' level. By minimizing on street costs and labor we reduce the costs.

By mass producing the legs and bridge components in a factory, it should be possible to reduce the cost of the skyway system to be close to that of a on gradient cycle way. Why is this ? The same reason a truck is cheaper than a man with a horse cannel boat. The cannel boat may not need gas but it takes longer than a cannel boat and the primary cost is people time. Gradient bike routes are labor intensive that can take months to construct, so perhaps skyway will reach that cost.

Skyways are likely to be cheaper then building roads, they require less cost for rights of way. More importantly they can be retro fitted into any urban system using as many existing rights of way as possible. Skyways are likely to be the lowest cost way of introducing a new choice of transport into a city.

Q. Isn't this all tried and untested ?

A. Well it depends upon what you mean by untried and untested. In Denmark 18% of journeys are made by cycle 'In Copenhagen has 300km of cycle lanes provided by its main roads within the center, the result being that 30% of the working population now use cycle lanes to get to work.' ( Brian Richards Future Transport in Cities SPON press). All the elevated cycle path concept does is permit the retrofitting of cycle paths into cities which where not built with the geographical advantage of being flat. Minneapolis has an extensive system of upper level pedestrian walkways so building above street level is not impossible. Pedestrian/cycle bridges are quite common, as are escalators and travelators. All the components have very long history. The carriage technology - the bike is very well known technology too. So the only thing which is untired is the will and finance to build one large system. Currently missing are the statistics of what traffic engineers call 'mode switch' - what percentage of the population will use this mode of transport if available to them. This is a requirement for the city planning departments especially if we see public money or even cooperation involved in the construction of many systems. Also at issue is how the presence of elevated cycle path would be to the shifting pattern of health in the kinds of communities which use it. This is shows the need for a good demonstration system to be installed somewhere.

Is the concept untried and untested - all the components are very very well known. Can I point to a demonstrational system no, but it would not take a long time to produce a few miles of experimental network.

Q. What is the biggest limitation of the elevated cycle network system ?

A. Distance, the average journey is about 30 mins for all forms of transport in Atlanta. At between 7 and 18 miles per hour that gives 3.5 and 9 miles of distance. Remember, 48% of trips in America are less than 3 miles so a strong network work with enough lane miles would be able to absorb some percentage of the current road trips. The elevated cycle network concept is not intended to replace cars, just congestion related trips, your not going cycle from Atlanta to New York over night. The elevated cycle network is about moving some local trips off the roads with out generating more congestion. By being cheaper then light rail, monorails and PRT this is reducing congestion at the minimum possible cost to the public purse. If we can move event 10% of potential trips to the elevated cycle network then this will reduce or eliminate congestion on many arterial. Remember short car journeys add disproportionally to the pollution generated so even a relatively small shift of potential journeys ( 5%) could have a larger impact on local air quality.

Q. If these skyways are so great wouldn't they become just and congested as the real streets and then everyone would go back to driving.

This is really two questions in one. Firstly yes it is possible that the skyways become very popular very rapidly and so they then suffer from the same kinds of congestion problems freeways exhibit. Bikes are much smaller than cars and are traveling at a lower speed. This requires a smaller headway ( gap between bikes), raising vehicles per hour. This might seem contradictory so let me explain further. If you need to get a large number of people out of a station up an escalator quickly the best thing to do is to make everyone stand as close as they can to each other. You might think if you get everyone to walk up it would be faster but its not true. For the highest number of passengers per hour you need remove the space between one person walking up and another. While walking up is the fastest thing for the individual to move the most people you reduce the empty space between them. Comparing bikes and cars then the narrower bike lanes would take a much higher number of vehicles to produce the same congestion rates as for a car lane. So adding a new car lane might increase a freeway by 1000 vehicles per hour but adding a elevated cycle network which is much much narrower would add 10000 vehicles per hour.

If congestion does occur we can do much more about it, we can build more elevated networks connected to the network. In the unimaginable situation of having one or two lanes per road we can then double up the network ( having two north lanes one about the other). There is an incredible amount of absorption capability in the system if necessary. Assuming a network is 6 deep and over every street in the city of your choice then eventually it too could be come congested ( we are talking millions of cyclists in a tiny area but it is possible). At this point like any other system the slow haul in the car is just as slow as the bike ride. People with then switch back to cars slowing the cars down until a new equilibrium is found.

Comparatively PRT and monorails have the ability to much larger ranges to elevated cycle networks. Elevated cycle networks are quite compatible with other forms of transport.

Q. Are you really forcing everyone to go out dump there cars and buy a bike do you really think the car lobby will let you get away with this ?

A. The bad news for the car lobby is that almost everyone owns a bike already. Secondly unlike many alternatives this is not exclusive, you can own a car and a bike ( many already do). There is not the slightest suggestion that you will have get rid of your car - unlike some dual mode systems. The principle of the elevated cycle network is to make sure that nothing slows existing transportation network down ( unlike buying more busses or light rail), nothing removes space from cars ( like HOV high occupancy vehicle lanes ). By concentrating a number of vehicles in a small network we are reducing congestion for a much larger number of car drivers.

Q. What about visitors to the city, how does a this proposal compare to PRT or Mass transit ?

A. Like cars we could have system where city visitors could rent bikes. There are a number of foldable bikes which you could take on a plane as hand luggage ( try doing that with your car). PRT and Mass transit would likely to be preferable for these kinds of riders. The elevated network is aimed at reducing congestion and pollution for commuters. Any new elevated network is likely to be a tourist attraction.

Q. Wont hundreds or possibly tens of thousands, millions of people die by cyclists coming down your off ramp on to pedestrians or in front of cars.

A. The down ramps for the skyway network are covered with s very soft rubber mat which absorbs most of the momentum of the cyclist down ward movement. By appropriate rails, doors and markings it would be very difficult to accidentally hurt someone. The skyway network would located stations on sidewalks so giving both cyclists and drivers to time to merge safely. For crowed city streets there is nothing preventing people walking the bike safely down the sidewalk to there destination. In some states it's also legal to cycle on the sidewalks.

Q. Is this a monorail ?

A. Well this is one wheel on one rail so perhaps it is :-)

Q. Why do you sometimes used 'elevated cycle lane' and sometimes use 'skyway' 

A. The elevated cycle lane is the genertic term for this concept. No matter who makes them, any claim for an elevated cycle way must remain true. A skyway is our term for an specific view of an elevated cycle way. So for example skyways have emergeny panic phones at intervals and have a lightwait prefabricated steel construction. An Elevated cycle way could be make from concreate or wood depending upon manufacture. As such the skyways aim to have minium visual impact and slender legs and which might not be true of an all concreate design.

 

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