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Old January 18th, 2012, 12:17 AM   #1
brisavoine
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Question about adequacy between traffic and infrastructures

I have a question for the forumers (I'm thinking in particular of ChrisZwolle, who seems to be an expert on this). We're having this discussion in the French forum, and one of the French forumers said this, which is typical of the mentality of some French forumers: "If you add a lane on a (urban) motorway, instead of reducing traffic congestion you will increase it." What do you think of this statement?

His reasoning, typical of many French people, is that there is no point expanding infrastructures, because they can never catch up with expanding traffic, so we must instead reduce traffic.

PS: If you're curious why we're having this discussion, it's because of the new population figures published in France today, which show a record high population in most French regions.
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Old January 18th, 2012, 10:53 AM   #2
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It depends on the situation somewhat. For example a short widening in an urban area almost never works because it moves the traffic jam to the next lane reduction. However, it can work if this prevents other connecting motorways to be congested too. For instance if the traffic jam doesn't block an important interchange anymore. The widening works as a buffer then.

There is also another important thing to be noted about urban motorway widenings. Often a widening may not completely reduce congestion, but if it goes down from say, 10 to 5 hours a day, it's still an important achievement. They reason this way in the Los Angeles metropolitan area.

Suburban and rural widenings usually have much more effect because they tend to have less nearby bottlenecks. For instance several widenings in the Netherlands have reduced congestion by as much as 95% at some points (which basically means the daily congestion is gone and there are only traffic jams in case of accidents).

Trying to reduce traffic has never worked anywhere. It's often pointed out by anti-road people that reducing traffic is much more effective than widening a motorway, however this has never been proven in practice. It's often just a way to make it a cash cow. The congestion charges in London and Stockholm have led to a temporary drop in traffic volumes in the charging area, but an increase in surrounding areas and outside rush hours. However, a congestion charge is very different from applying congestion charges to a motorway network. The only country who uses this is Singapore and that's a city state.

(auto) mobility is a basic need and is far less price-elastic than is often assumed.

A road widening usually results in higher traffic volumes. However, this doesn't mean it results in more congestion. Adding one lane means the capacity goes up by 4 000 vehicles per hour or 40 000 vehicles per day. Some of that is filled up by people changing travel times, but adding 30% more lane capacity doesn't equal 30% less congestion, often it equals 95% less congestion because the bottleneck is gone.

Large metropolitan areas will probably never be devoid of any congestion, because the population is just that big and millions of people have travel needs in the same timeframe. However it's no excuse for doing nothing at all. If your metropolitan area grows, so will your schools, sewage systems, hospitals and retail. Why not the road infrastructure?
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Old January 18th, 2012, 02:42 PM   #3
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brisavoine, please give me the link to the discussion over this matter on the French forum !

Anyway, I don't know which part of France brisavoine is from, but here, in the Northern part of the Île-de-France region, we have four major problems with traffic:

A) the A15, that goes from the N14 (Cergy-Saint-Christophe) to the A86, not continuing towards Clichy although the space for the other carriageway has already been prepared around 20 years ago

B) the "Francilienne" ending, which has suprisingly many opponents (part from the N184 at Saint-Ouen-L'Aumône to the A13 in Poissy), although traffic volumes on the N184 in Éragny-sur-Oise is very high and there's often traffic congestion because of the numerous intersections.

C) The T3 tramway ending, which led to a complete closure of the commonly called boulevards des maréchaux near Porte de La Chapelle, leading to additional congestions on this part at all time. In other terms, they cut an alternative ringroad to the Périphérique in the name of "ecology".

D) The A16 motorway/N1 expressway: the expressway section ends to early, leading to high traffic congestion within Saint-Denis, Sarcelles, etc. (no connection with A1)

This is the exact point of what brisavoine describes: French people (& especially politicians and so-called experts) live in a dogmatic illusion that not increasing motorway/expressway capacity will lead to a reduction of traffic volumes. Not only the traffic is getting worse and worse, but it also goes against the ecological intentions of some people, as congestion leads to more pollution.

Maybe there will be a temporary decrease when the new "ceinture" train lines will appear in the Paris region, but I don't really believe in it. The Île-de-France region is about 1/6 of the French population and there are more & more people moving to it.

Most of the people who move out of the Paris region (because of the congestion and the high real estate prices) still stay connected to it because of their workplace. And as they often move to parts where means of transportation are insufficient or inexistent, they've got to use their cars to go to Paris or its close suburbs ...
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"Richtgeschwindigkeit" should be the default system in all EU motorways & expressways & lane indiscipline should be harshly fought! Down with radars on motorways!
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Old January 18th, 2012, 03:48 PM   #4
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Quote:
Originally Posted by GROBIN View Post
brisavoine, please give me the link to the discussion over this matter on the French forum !
Here: http://www.skyscrapercity.com/showth...8#post87664158

@ ChrisZwolle: thanks for your answer!
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Old January 18th, 2012, 06:05 PM   #5
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Merci ! & also dank u wel to ChrisZwolle, who confirms my arguments when debating with local people who disagree with me on this matter ...
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"Richtgeschwindigkeit" should be the default system in all EU motorways & expressways & lane indiscipline should be harshly fought! Down with radars on motorways!
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Old January 18th, 2012, 07:33 PM   #6
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I agree with Chris. If you do not elaborate complexity of the congestion problem it will be dislocated to another junction or road stretch. However,that is mostly a matter of policy of a city. There are a lot of methods today to solve urban congestion in traffic but it depends on power of voters and availability of resources. As I know France has financial ability for that porposes and if it is necessary to have high LOS(level of service) on some urban roads you have to better organize local community.
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Old January 20th, 2012, 02:55 PM   #7
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This journal paper makes interesting reading:

http://www.informaworld.com/smpp/tit...ent=t713673447

Essentially all major city centres in the UK have experienced a reduction in traffic but congestion has paradoxically increased. Why? Because local authorities have continually been reducing road-space for cars. It seems to follow a "designer congestion" approach - if you create obstacles traffic will go elsewhere.


I guess anti-road people have caught on to this, perhaps by making parallells with their own experiences. They may have bought a wardrobe, filled it with junk, then bought another one to store more crap in, before boarding the loft out and filling that with yet even more junk. See where I'm going with this?
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Old January 20th, 2012, 04:22 PM   #8
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I can't follow you guys. If city authorities reduce space for cars, the smart citizen will be caught on a jam the first day, maybe also the second day, but the third day he will take the bus.
If people continue using the car even if they're caught in jams all the time, they are not very clever.

I love cars and I love driving, but I never drive inside a city, at least not during the day.
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Old January 20th, 2012, 04:37 PM   #9
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Fact is that even though there is congestion, driving a car is still faster and more flexible and reliable.

A year back there was a study about traffic congestion in the Netherlands and they found out that the average rush hour car trip still takes twice as much time if you use public transport.
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Old January 20th, 2012, 06:23 PM   #10
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Quote:
Originally Posted by ChrisZwolle View Post
Fact is that even though there is congestion, driving a car is still faster and more flexible and reliable.

A year back there was a study about traffic congestion in the Netherlands and they found out that the average rush hour car trip still takes twice as much time if you use public transport.
Time is not the only issue here.
I don't know about cities in the Netherlands, but today I went to the dentist's by bus and took 15 minutes. If I went by car, I would take about 10 minutes and spend other 15 trying to find a spot where to park, and pay the parking which is as expensive as a bus trip.

And it was far more relaxing letting the driver do the job.
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Old January 21st, 2012, 01:34 PM   #11
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Quote:
Originally Posted by g.spinoza View Post
I can't follow you guys. If city authorities reduce space for cars, the smart citizen will be caught on a jam the first day, maybe also the second day, but the third day he will take the bus.
If people continue using the car even if they're caught in jams all the time, they are not very clever.

I love cars and I love driving, but I never drive inside a city, at least not during the day.
But what if the smart citizen doesn't live close to the city centre and doesn't enjoy the luxury of good access to a good value, clean and quality frequent bus / metro / train service?

Yes there will be a good proportion of people who can, will and indeed should travel into a city centre by public transport or by walking and cycling. But there will always be a residual demand for travel into a city centre by car, as there will always be people who don't benefit from good access. This is a point that the green left ignore and instead preach morals about how evil people are who dare drive into a city centre.

In my own experience, i'm with spinoza with loving cars and driving. I agree that driving is best enjoyed doing the occasional roadtrip or out visiting family and friends, rather than commuting to work. I have shops that I can walk to and good public transport that gets me into town without the hassle of driving. As I also work at home, I donlt have to commute either.

I do however, appreciate that whilst its good to get people to leave their cars at home, some don't have that option. Hence moralising and penalising people who really don't have a choice is really harsh. To this end transport policy needs to bear in mind the need to strike an appropriate balance rather than develop policies that have a clear prejudice against some ways how people travel, in this case car travel. In this sence I do have an issue with how people love to politicise transport - associating the car with the right and evil capitalism and the bus with socialism, environmentalism etc - it's BS at it's very best.
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Old January 21st, 2012, 01:39 PM   #12
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But what if the smart citizen doesn't live close to the city centre and doesn't enjoy the luxury of good access to a good value, clean and quality frequent bus / metro / train service?
The answer is simple. Take your car to the nearest P+R parking, and then take the bus. Problem solved.
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Old January 21st, 2012, 01:47 PM   #13
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Quote:
Originally Posted by sirfreelancealot View Post
Essentially all major city centres in the UK have experienced a reduction in traffic but congestion has paradoxically increased. Why? Because local authorities have continually been reducing road-space for cars. It seems to follow a "designer congestion" approach - if you create obstacles traffic will go elsewhere.
Then, cities shouldn't complain when their high streets start losing the appeal to outskirts malls and satellite office parks. Sure, some cities like London or Glasgow will still retain nicer activities in central areas due to tourism or the mere sheer number of the people living in their metros, but when it comes to - say - Leeds or Plymouth, that is not the case.

Moreover, the argument is pretty much non-sequitur: there are physical limitations on how much traffic a transportation infrastructure can carry, be it a subway or a highway or whatever. Theoretically, if you closed all streets of the City of London, plus all subway stations, and put some 30m-high fences around it, traffic in the City would dramatically reduce, as people would be only able to access it via helicopter, hot-air balloons or rappel over the fence.

The problem I have with this "reduce capacity and traffic will go away" mentality is that it will usually be taken side-by-side with restrictions on the freedom of developers to build better (for car traffic) suited office parks or large malls to counteract the effects of more difficult traffic on the the "traffic calmed" downtown. It is like politicians trying to force the population not to drive downtown because of reduced capacity, but also not drive anywhere else because of planning limitations.

Some of the more radical activists on the "reduce road capacity to reduce congestion" go as far as suggesting that overall speed of commutes should be "lowered", even in public transport (with abolition of commuter trains than "shove" people from 50, 100km into downtown in the morning and take back in the afternoon and their replacements by all-stop services, streecars and all-pedestrianized large areas), to "force people to make wiser housing choices based on their employment". The really wackos in these department want all but to dismantle fast rail links, airlines etc. to "reclaim the connection of people and the land they live in, buying local food, knowing the farm that produces it, and working in more traditional crafts that give a sense of purpose in life" - Italy is full to that crap, usually losers with 40 y.o. living with their moms that attended social studies university courses.

And attacking a lawful behavior like driving for any political reason is unacceptable.

Quote:
I guess anti-road people have caught on to this, perhaps by making parallells with their own experiences. They may have bought a wardrobe, filled it with junk, then bought another one to store more crap in, before boarding the loft out and filling that with yet even more junk. See where I'm going with this?
Cars are not junk and mobility is not a good, but a service whose value is zero after used. I can't "store" trips I don't take for a month and take them all on Sundays, 3am-8am.
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Old January 21st, 2012, 01:49 PM   #14
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The answer is simple. Take your car to the nearest P+R parking, and then take the bus. Problem solved.
That will usually increase travel time, because once you are in a car travelling from other city, unless you are going to a very high density area (like London's Canary Wharf for instance) with trains and/or subways leaving every 4 minutes or less and taking you straight to the place you want to go, park-and-ride will be a money-saving, but time-losing proposition.

What cities can do to improve the situation is build massive underground parking facilities that unclog the problems caused by drivers seeking a on-street parking spot. This is the major source of congestion in busy areas in many cities: drivers screening the curbside for a spot.
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Old January 21st, 2012, 02:01 PM   #15
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Note that the far majority of traffic on the European urban motorway networks do not have an origin or destination in the historic city center, but rather in residential, suburban, industrial or office locations. P+R facilities could be an option but is rather impractical for shopping unless you're planning to walk around with 4 or 5 bags all day and is indeed not really an alternative for short-term visits because of the additional travel time and hassle involved.

Another problem in some countries like the Netherlands is that they forbid good accessibly highway retail locations, but don't want those people to go into the city center by car either, which turns this policy into a cash cow, because many Dutch cities make a significant profit from parking fees. The 10 largest Dutch cities made an average 35% profit from parking. Some are not profitable due to parking revenue being transferred to other means (such as public transport). Dutch parking revenue went up by 40% in the 2005 - 2010 timeframe.
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Old January 21st, 2012, 03:16 PM   #16
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P+R facilities could be an option but is rather impractical for shopping unless you're planning to walk around with 4 or 5 bags all day and is indeed not really an alternative for short-term visits because of the additional travel time and hassle involved.
This could be easily avoided if enterprises, shops and business sites in the city centers would be required to construct their own parking facilities, or cofinance the city's parking facilities, with a prospect that customers, employee, visitors of those establishments would get discount or free parking, whereas the rest would have to pay the full price.

This would limit misuse of such parking places by car owners that could indeed make use of a P+R, which I learned to use when on touristic trips. It is rather convinient and time, costs, saving (I dont have to be stuck in the city traffic when I want to go in and out the city in the rush hours).


It is rather stupid when even in a small place like Meppel the local supermarket in the broader center has attached parking lot, however the supermarket visitors have to pay normal parking fees.

Last edited by Surel; January 21st, 2012 at 03:25 PM.
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Old January 21st, 2012, 03:25 PM   #17
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This could be easily avoided if enterprises, shops and business sites in the city centers would be required to construct their own parking facilities, or cofinance the city's parking facilities, with a prospect that customers, employers, visitors of those establishments would get discount or free parking, whereas the rest would have to pay the full price.
If every retailer did this (like many do in many US cities), everyone can park a car easily on their place of destination, and thus street parking becomes cheap (or else nobody will park there). If you take out employees, costumers and visitors, you are essentially leaving out only people driving there for the lulz or to visit somebody's residence.

Organized block-wide underground parking is nice because it also reduces costs. It is cheaper to build one 1000-place parking facility than 40 25-place facilities.

Quote:
This would limit misuse of such parking places by car owners that could indeed make use of a P+R, which I learned to use when on touristic trips. It is rather convinient and time, costs, saving (I dont have to be stuck in the city traffic when I want to go in and out the city in the rush hours).
The number of cities where leisure tourist traffic by car that is not directed at a hotel is significant is quite small, e.g., people who go to a place, by car, with no intention of parking it overnight, and not on a shopping trip.

Quote:
It is rather stupid when even in small place like Meppel the local supermarket in the broader center has attached parking lot, however the supermarket visitors have to pay normal parking fees.
The supermarket probably makes a profit out of this because if it didn't, it would offer free parking. And some cities maliciously disallow "free parking" in downtown areas to avoid competition to the public parking garages. That is the case in Tilburg at least: if a premise wants to offer free parking in the central area, it has to pay a tax per parking spot offered for free. Or reimburse costumers for regular parking fees.
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Old January 21st, 2012, 04:37 PM   #18
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If every retailer did this (like many do in many US cities), everyone can park a car easily on their place of destination, and thus street parking becomes cheap (or else nobody will park there). If you take out employees, costumers and visitors, you are essentially leaving out only people driving there for the lulz or to visit somebody's residence.

Organized block-wide underground parking is nice because it also reduces costs. It is cheaper to build one 1000-place parking facility than 40 25-place facilities.
Isnt this in accord to what I said? Sure smaller retailers in the city centers would have to cofinance big projects... it would make no sense to create one or two parking places under their shops.

But this system would greatly decrease the risk that you would be searching for a parking place in the center also reducing the cloging due to many cars browsing the streets in vain searching for parking places.


Inner city retailers most of the times are not ones that you need to visit with a van to get your shopping done, and if yes, they should be able to provide the transport anyway. Car-wise shopping is indeed done at the outskirts of a city. It makes also perfect sence. If you live in the inner city, you can do the groceries by simply dragging your shop bags home, because the distance wont be much bigger then from a big outskirt shopping center to your car at the parking lot there.

Most of the innner city business is anyway services thus you dont need to drag something to your car.

You dont visit pubs and clubs with your car either...

I did not read studies on the origin of a traffic directed to the city center, but I would say that most of the times it is just (for a reasonably big city in Europe, with public transport)

a) people from outside the city doing serioius business downtown
b) people from outside the city driving to and from work
c) customers from outside the city
d) peple living in the city travelling to another city

However I would gess that most of the traffic in the city center originates from

a) people from inside the city prefering car to public transport moving between different parts of the city.

=> thus I would think that the only ones that need the extensive parking areas inside the city center are the outsiders. Their problem would certainly be solved by organized block wide parking as you nicely named it.
(given that parking for people living within the city is provided at the housing they occupy)
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Old January 21st, 2012, 04:49 PM   #19
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High-end commercial parking spots can be paid back within a few years. A typical underground parking spot costs about € 40 000 - 50 000 to construct and operate, which means at € 3 an hour and 12 hours a day occupied, it pays itself back in about 1 300 - 1 400 days, or 3 to 4 years. Most underground parking structure have a lifespan that is much longer than that, so even if the occupancy rate falls, it can still pays its cost back quite easily.

Residential parking is usually less profitable, due to the fact very few people are willing to pay commercial fees for parking their car, because it can cost thousands of euros per year. So they can get a permit at a reduced cost, but the waiting list can be up to years in some areas.
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Old January 21st, 2012, 05:10 PM   #20
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I guess in the end different people want different things - personally I way prefer the feel of European towns which are largely full of older buildings and free of big roads and big car parks, compared with say American cities, but to some people (probably a majority) the apparent convenience of being able to drive everywhere is more important... but I would argue the 'new towns' in Britain which were built around the car in the 60s aren't viewed as remotely desirable places by most, even if the locals do get around with less congestion
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