kickstart

I agree, climate change has been over played by all parties involved in its debate, and those who profit from both points of view. It's been forced to be a pick sides issue leaving little emotional middle ground, saying bike infrastructure is good for the environment will automatically make it unpalatable to many.

Roody

I think it's fine to say that bike's are good for the environment, because they are in many ways, and it's a good selling point for them and their infrastructure. At least, that's something people who drive a lot are always telling me when they find out I'm basically carfree: "That's cool--it's really good for the environment and you get good exercise. I wish I could do more of that." But for a small (and very vocal) segment of the population, climate change specifically is purely negative, and doesn't have to be part of the bike lane argument.

tyrion

I wasn't really arguing that we should politicize it just pointing out that it is politicized. The "usual suspects" are putting pressure against bicycle infrastructure. Oil companies have an interest in keeping people driving cars.

It depends on locale. In San Francisco making that linkage will get you bike lanes, in Houston, maybe not.

But I think we are in agreement that, on the politics of climate change, we need to pick our battles carefully and strategically.

CliffordK

It only has a negative impact on traffic if the government cuts down, say from 4 lanes to 2 or 3 lanes. If the number of traffic lanes remain constant, I believe it has a positive impact on traffic.

Add to your list, like a road shoulder, a bike lane provides a safety buffer for cars. Driving on a narrow shoulderless road can be dangerous.

If bikes are good for the environment, does that necessarily imply that bike lanes are also good for the environment?

Consider the albedo of miles of black surface.
How much tar or concrete goes into making a bike lane? How much energy?

Around here, the best off street paths get a fair amount of bike traffic, but even at best, perhaps a density of 1 person per quarter mile at any one time. The low traffic paths might get 1 person per couple of miles. It is hard to compare that to the number of vehicles on the road.

I love our off-street path network. But, I'd be riding whether or not there was an on-street path network. Perhaps the biggest advantage of the paths is that they encourage "newbies" to get out and ride.

I narrowly missed a "right hook" across the path just after the light turned green, a few days ago. I was running it bit hot going down the path. I didn't see the car signal, whether or not it was, I don't know. But, came very close to a collision. Had there not been a bike path, I would not have been passing on the right, and there would have been no potential for impact.

Anyway, in general, I like the paths. But, it does seem a bit selfish to have a long path just to myself. And from an environmental view, they may only be a benefit for their publicity value, and not when one considers the resources that go into building them.

Roody

Yes, although that isn't the only consideration. Bike lanes are often good for the built environment. They raise adjacent private property values and also make publicly owned property more valuable--parks and public buildings as well as the street network itself. Above all, they make the entire community more safe, pleasant, and desirable to live in.

If the paths aren't getting much use, there might be something wrong with them. A lot of bike paths are basically "paths to nowhere." That is, they don't connect locations that people actually want to travel between. In some cases, the paths were built where it was cheapest to get easements--often because they're in pretty undesirable locations.

Other paths were designed primarily for recreational and fitness riders, not for those who are actually riding for transportation. There's nothing wrong with this, but it makes more sense to think of this type of path as a "linear park" rather than as a "road for bicycles." They should be financed through the parks department rather than the streets and highways department.

A well-traveled road for bicycles usually connects a number of popular destinations such as shopping areas, residential neighborhoods, medical centers, schools, and workplaces. If the path is also scenic, safe, and fun to ride on--those are great bonuses.

Also, at this stage of their development in North America, the main environmental cost of a new bike lane is a bucket of paint and a few metal signs. We haven't gotten to the point of making elaborate ramps and tunnels for bikes, as they have in the Netherlands and a few other countries.

catgita

Not entirely so, and momentum is building.
America?s 10 best new bike lanes of 2015 | PeopleForBikes
Portland has a few major bike/ped/transit only bridges in the works, and my local MUP trail is slowly being upgraded with better tunnels and ramps to improve flow.

It is not surprising at all to see pushback on bike and transit lanes in LA of all places, and while there is still so much low hanging fruit for projects, it won't slow progress much. The council resolution was a surprise to me not for its content, but for its timing. I don't usually expect such leadership from our leaders. The bikelash will pass.

CliffordK

I wouldn't say there is anything wrong with the path network here in Eugene. The riverfront greenway paths are great, and I find them to be very handy for getting around to where I typically ride. And they get a fair amount of use, although perhaps 3/4 of the use is purely recreational, and 1/4 being commuting/errands. The streetside paths along the major arterials are good for going places quickly, but of course, have all the issues of being along a major arterial, and would be used primarily for commuting, or less frequently for recreational riding.

If say, 10% of the population bike commutes, how frequent is that? A few times a month? My guess is that the average bike commute in Eugene is less than 4 miles each way. Car commutes can be much longer. And, other than those people who are generally car free, shopping trips, or longer distances would be done in a car. So, mile per mile, ignoring through freeway traffic, it is probably closer to 1% of the miles on bike, and 99% in cars. Maybe Eugene is skewed a bit by the University, with Springfield skewed in the opposite direction. In the winter, the numbers may even be less.

Anyway, in many places, a dedicated half car lane doesn't get a lot of traffic.

It may be a bit better in the larger cities. But my observations in Portland is that it isn't much different. There are a few paths that are popular for recreation such as Terwilliger, and down along the Willamette river, but pretty much everywhere else the paths are under-utilized.

Dedicating 4 or 5 feet of pavement on the side of the streets to bikes is a lot more than a few buckets of paint, although some might be relabelling wide shoulders already on some roads. In other cases, roads will be widened for paths, or lanes or parking will be dropped.

Eugene actually has quite a few major dedicated bicycle/MUP bridges across the Willamette, and McKenzie rivers. The Willamette is a good sized river in Eugene, but it is a lot smaller than it is in Portland, plus Eugene doesn't have to deal with commercial shipping traffic that Portland has.

• Bridge across Willamette, East of Campus
• Bridge between Campus and Autzen Stadium
• "New" suspension bridge at Alton Baker Park. (somewhat redundant with paths already on the Ferry Street Bridge).
• Bridge at Valley River Center
• Bridge Near Marist HS
• Train Trestle Trail across McKezie near Armitage Park.
• A number of smaller bridges including another Train Trestle across a canal behind Bike Friday.
• There are also several places where bike paths along waterways pass under vehicle bridges.

Anyway, the riverside MUPs are fairly heavily used with a lot of recreation users, and some of it is having reasonably good connections, and bridges. The recreational benefits are HUGE. But, the total number of users is still less than vehicles on nearby roads.

Trevtassie

HTF is saying bicycle infrastructure is fighting climate change intellectually dishonest? If somebody feels more comfortable riding a 15kg bike than driving a 2 ton car because there is a dedicated bike lane then bike infrastructure has had a positive effect on GHG emissions. Unless of course it's the usual concern troll meme. Which given the rest of your post, it probably is. Nasty environmentalists associating bikes with the environment...

tandempower

Riding a bike fights climate change in more ways than just being a light vehicle that doesn't burn fuel. The more people ride bikes instead of driving, the less traffic on the roads. Less traffic means less lane demand, which means the possibility of installing more trees medians, which is a step toward reforesting deforested areas, which absorbs sunlight instead of converting it to heat, which also helps retain ground moisture, which further cools climate and helps revitalize tree and plant growth.

The problem is you can't make everyone give up driving all at once and reforest cities immediately, because then the energy/heat-absorption effects would be immediately perceptible. As such, the best we can do is make cycling as good an option as possible and hope that people will see the light, all the while waiting for the deniers to stop throwing monkey wrenches in the process of expanding the cycling option through infrastructure reform.

tandempower

It doesn't really matter because without bike lanes and paths, society is on a dead-head path to environmental destruction and resource depletion. Automotivism can't just eliminate bike lanes to become sustainable and not having the bike lanes makes it that much harder for people to choose to bike.

Of those who don't deny automotivism is a problem, only a few see it as their responsibility to utilize alternatives for the sake of growing the popularity of cycling. Culturally, there was more wherewithal a few years ago to take initiative individually for creating social change than there is now. I have read research that people orient more strongly toward socially responsible behavior during or in the wake of recession. After economic growth has been re-stimulated for a while, social responsibility gets eclipsed by social pressure not to complain because more people are doing better financially, never mind the environmental costs of the economic growth.

You're doing the right thing by riding it, then, because most people don't want to be the first and/or only person utilizing a bike path. First, it takes the really independent people deciding on their own to go out there and take advantage of it. Then come the avantgarde who view it as a minoritarian trend and see it as a daring social risk to follow suit. Once a significant critical mass of people build up, then comes the masses flocking in droves because they don't want to miss out on the hype, though they can get discouraged if industries lobby against a trend as being a threat to jobs or otherwise negative in some way, as cycling was a few years ago when its popularity was really snowballing.

Smallwheels

As an interesting tidbit; a couple of decades ago in South Africa where there is a lot of heat and not a lot of water, the government and environmental organizations began removing trees because each full grown tree sucks up at least 100 gallons of ground water per day. This was a different kind of conservation measure.

cooker

Do you have a link to that? It seems quite dubious. Where they a foreign, invasive species of tree?

tandempower

It's an interesting scientific discussion, one I'm not sure we can have in this thread. Still, a tree is somewhat like a pond whose water is protected from evaporation by converting the energy into photosynthetic growth instead of heat. Yes, water is broken down into hydrogen and oxygen during photosynthesis, but the shaded ground under the tree stays cooler and thus moister.

If rain water seeps underground without a layer of trees and plants in-between, the water is going to flow faster into aquifers, which channel into underground rivers that flow to the sea. The more trees are cut down, the hotter and thus dryer the topsoil becomes. Heat rises off the hot ground and dries up whatever moisture is condensing above as clouds. Rain grows increasingly more scarce. You need ground-level cooling to allow clouds to form, condense, and precipitate. You might get lucky and have a cold front and warm front meet above your hot dry city/desert and rain down some water blown in from elsewhere, but without a spongy layer of trees and plants to hold the water and allow it to gradually seep underground, there won't be a steady supply of groundwater from the surface.

What you're saying, though, is that the tree roots can pull water up from under the ground and release it into the air faster than it would evaporate from underground aquifers, which are theoretically protected from heat if they are deep enough. By extending this logic to the broadest ramifications, people everywhere would be cutting down trees in the hopes of building up underground aquifers that don't flow out into the sea. The treeless surface would then get hotter and dryer and convey more hot dry air into the atmosphere.

What effect would this have on precipitation patterns? Hotter winds mean more water gets absorbed into the atmosphere before precipitating. What is going to be the source of cold fronts to squeeze the humidity out of the air? Night and winter shading of the planet brings down temperatures, but won't the storms be more torrential as a result of more water getting absorbed by the air before it encounters sufficient cold to rain down? And if rains are more torrential, won't they carve channels to the sea more forcefully, whether above ground or underground?

To me it just seems obvious that reforestation mitigates ground temperature and slows evaporation by absorbing sunlight instead of converting it into hot air. Trees shade the ground to create the moist conditions that allow their offspring to spread. Some species of tree are better suited to dryer conditions than others, but generally I think you can say that a drought-oriented species, like cactus, shades the ground and if enough cactuses spread and shade enough ground, other species are able to grow because the cactuses have paved the way by helping the sand hold moisture longer than if it was exposed to direct sunlight. So soil-building and reforestation are a slow process but one that is necessary for the long term revitalization of the planet.

Trevtassie

Eucalyptus from Australia are known for lowering the water table and were planted extensively all over the world. Their roots can penetrate over 100 foot down and they suck up huge amounts of water. Not good if you get your water from a well. Here in Australia some farming areas have the opposite problem, the eucalypts were cut down to create farmland and the water table rose, bringing salt water with it. So there has been a need to try and replant them to lower the water table.

tandempower

Do roots really 'suck up' water or do they mitigate moisture levels underground? A root network spreads out underground, much like the branches do above ground. The roots thus make the ground spongy and moist. Maybe water doesn't pool up as much underground because the root systems spread it out more broadly, but I think the total amount of water throughout the ground remains greater because of the broad expansiveness of the root networks.

It would make sense to me to reforest the land as much as possible except for isolated areas cleared for farming, or even to use more intensive above-ground farming techniques. If surrounding lands are well-forested, I would expect the spongy ground to absorb more water, which should trickle down into aquifers that can be tapped for farm irrigation. Logically, if trees 'sucked up' more water than they helped the ground retain, they would kill themselves off in the process of doing so. They must have evolved to act as a moisture-thermostat for the ground; otherwise they couldn't reproduce and spread as they must to survive.

Trevtassie

Eucalypts definitely act like pumps and lower the water table. They also tend to suck any moisture out of the soil around them. They are good at intercepting surface moisture too. But if you want trees and have a dry environment they will work well, as long as you don't mind out of control forest fires, they burn well. https://www.anbg.gov.au/cpbr/cd-keys...html/learn.htm
Anecdotely, I've been 3 levels underground (300 feet) in old mines and seen roots coming out of the roof of a drive a (tunnel) and into the floor, chasing water several levels below.

tandempower

If the trees would suck up all the ground water and dry out all surface moisture, how would they reproduce and spread? Why wouldn't they die out because they use more water than the rains can replenish in the soil? A forest has to manage its own ground-moisture levels and nutrients to grow and spread. If a forest grows up, dries out, and then burns down, there are certain species adapted as pioneers of the scorched soil, which gradually revitalize it so that other species can return as well.

Either way, moisture levels build up as the ground gets better shaded by forest densification processes. Strip the land of all trees and other shade-producing plants and it will soak up more direct sunlight, dry up, and heat up more causing more hot convection currents that dry up whatever atmospheric moisture is collecting above. People tend to like dryer air because it feels cooler and grows less mildew, etc. but water has to condense over land to seep into aquifers and since aquifers flow to the sea, that water can better trickle down slowly from moist underground root networks than flushing quickly down and through the aquifer because there is no spongy layer of root networks and decaying biomass to mitigate it.

Roody

Are they growing trees in the bike lanes?

cooker

Sounds like the eucalyptus may be an exception

tandempower

Maybe, but then I would want to understand why, how it works, and how it propagates if it fails to keep the soil around it moist enough for its seeds to sprout and for saplings to grow.

edit: I just read up on Eucalyptus on Wiki and they do indeed seem to be a species especially suited to drying out land, prone to fire because of the oily resins produced. Normally, I would expect drought-tolerant trees to emerge and spread to shade the ground and promote reforestation but it sounds like these Eucalyptuses spread through Australia causing wildfires that would destroy reforestation growth. I suspect similar problems will result from North American efforts to restore certain species of pine that are more fire-prone, in the name of species diversity!

Anyway, I don't know what hope there is for Australian reforestation if Eucalyptus have dominated for such a long time. Wiki mentions collecting the fallen branches for use as fuel. Idk if it would be wise to cut them down if there aren't other trees already growing to take their place. If there's one thing that seems clear, it's that unshaded ground bakes dry making it very difficult for new plants and tree cover to survive. Of course, I don't know what other tree species can do well in the Eucalyptus shade; maybe pines?

cooker

So it seems like, depending on climatic and soil conditions, eucalyptus can either conserve water or deplete it, and in some cases it can affect water quality. So, depending on the circumstances it may be appropriate to either plant/retain eucalyptus, or remove it, for environmental reasons.
Proceedings. Regional expert consultation on eucalyptus. Volume I.

McBTC

Many streets are ill-suited for bike lanes which is why oftentimes if all possible the 'official' bike route is winds through neighborhoods, and is well-marked, safer and saner than thinking a cyclist would rather run the risk of being speared by a car door and cut off at every intersection.

cooker

To try to bring the side topic on trees back into relevance, one benefit of putting bike lanes or otherwise encouraging bike traffic on residential as opposed to commercial streets, is there may be a lot more shade. Certainly I take the availability of shade into account in planning my commute. So this is one area where bike and car traffic may have different priorities. As well, residential streets and neighbourhoods can be modified to discourage car traffic while permitting or facilitating bike traffic, which the residents may arguably find less objectionable or noxious than motor vehicles.

tandempower

Disciplining traffic can be difficult.

Installing bike lanes on more commercial roads might be a good excuse to add treed medians and sidewalks. Part of integrating pedestrian traffic into an area includes making commercial traffic corridors more friendly to cycling/pedestrians as well. After all, people need to be able to walk/bike to work and shop on those commercial roads too, no?

tandempower

I think the following quote from this article is assumptive:
It sounds like something added to appease proponents of tree-cutting for business purposes. Fields of scrub and grass often dry up if not watered. There are areas where fields cleared of trees are dried up from the sun within a short distance of forested parcels that remain much greener. The temperature is also noticeably cooler when you enter the shaded/forested area. Most importantly, cool air has to build up to cause precipitation so clearing trees reduces the potential to build up the cool air that brings rain, dew, etc.