Evaluating urban planning initiatives to increase active transportation

Ottawa Sun: Laurier St. bike lane in Ottawa (ON), Canada

Urban planning and epidemiology need to become better friends. Rigorous epidemiological studies that assess the health impacts of urban planning interventions are desperately needed. These studies can more reliably tell us what works and what doesn’t, and therefore where best to put our hard-earned tax dollars. I’m not sure why they are lacking. Money? Time? I guess they are all good excuses. But in the grand scheme of things, I would settle for even just a simple before-after study – something that I think is more than feasible.

Ottawa recently implemented a segregated bike lane pilot project on Laurier Street, running from Bronson to Elgin Streets. The lanes are blocked off from traffic with concrete curbs, plastic poles, parked cars and planter boxes. New road markings (including those gross green boxes) and signs tell cyclists where they should be. Most on-street parking has been removed and some bylaws have even changed, such as no right turns on a red light, which protect cyclists from absent-minded motorists. The project is part of the City of Ottawa’s plan to become a greener and more sustainable city.

All of this is great news for cyclists (and environmentalists), even though it has received some grumblings from residents and merchants on Laurier Street who have lost parking spots as a result. Since the lanes were open on July 10, 2011, almost 117,000 people have used them (that is, passed a counter at Laurier and Metcalf). Wow, that sounds like a lot of people…but wait a sec…How many cyclists used Laurier before? Maybe the same number of people used Laurier last year from July 10^th to September 28^th, 2010. So this number really tells us nothing. We have no idea what the ‘success’ of the pilot project is defined as either. Is it a certain percentage increase in the number of users, fewer accidents, more commerce, increase in physical activity, etc.? The main points I am trying to make here are that the city could have at least placed a counter in the same location BEFORE they implemented the project, as well as determined significant outcomes a priori and communicated those to the public. I don’t think it would have been that much more costly.

 I’d like to highlight that this would be something that is needed in the very least. These types of designs that use counters to count the number of users before and after are not robust against bias and cannot capture all that we would really like to examine. Here are a few examples why: 

• We can only count users and not individuals so likely we are double, triple counting, etc. Perhaps increase in usage is only by those people that already cycle on the road 
• If counters are electronic, I'm not sure if they can discriminate between cyclists and people that shouldn't be using the lane (such as skateboarders, motorized scooters, etc.)
• We cannot determine impact on the health outcomes of individuals living nearby, such as increased physical activity or decreased obesity
• Increase/decrease of cycling on Laurier could actually be due to other factors that we have not accounted for or reflect only secular trends (not due to the new lane)

I have had a very hard time finding an urban planning intervention with the intent of increasing active transportation/physical activity, or decreasing obesity, that has been well conducted. There is also the added caveat of residents actually knowing about the change to their environment. For example, if they don’t know about a new bike lane, trail system, or park how can they use them?

A study by Evenson et al (2005) perhaps is a basic model to follow– with, of course, some upgrades (e.g. addition of a control group). They set out to determine if a new rail trail built in Durham North Carolina (US) significantly increased time spent in leisure activity, moderate and vigorous physical activity, and active transportation of residents living nearby. 

Participants 18 years or older living within 2 miles of the trail were randomly recruited to participate in two telephone surveys conducted before and after introduction of the trail (n = 366). Questions were largely based on the Centers for Disease Control and Prevention’s Behavioural Risk Factor Surveillance System.  The researchers did not find that the new trail had any effect on the outcomes they looked at. There were some issues with the study which may explain why they did not find anything. Some examples include: 

• The after measurement occurred just 2 months after the trail opened – this may not have been a sufficient amount of time (e.g. residents may still not have known about it). In fact, 38% of respondents said they weren’t aware of the trail [Correction - this should be 11.3%, 38 was the n]

• The after measurements occurred in November, whereas the before measurements occurred in summer and early fall. In Canada at least, we tend to be outside less as the winter approaches versus in the summer
• Low response and retention rates. The people who responded were likely not representative of the population (they already had high baseline rates of activity). What were the people who didn’t respond like? 

There are some other issues that I won’t get into but I think it’s a basic study that could easily be implemented by urban planners, with the help of public health professionals or universities with epidemiology or program evaluation departments (to increase the study’s robustness which is very important)! Who knows, maybe the City of Ottawa has done all of this and we just don't know about it - I'll give them the benefit of the doubt. Regardless, I truly think this is a worthwhile and necessary transdisciplinary endeavour that will benefit society as a whole. And don't get me wrong, I am for increasing biking infrastructure. I just want to make sure we can quantify its benefits and that we do it in the best possible way.     

Evenson, K., Herring, A., & Huston, S. (2005). Evaluating change in physical activity with the building of a multi-use trail American Journal of Preventive Medicine, 28 (2), 177-185 DOI: 10.1016/j.amepre.2004.10.020

Safety and biking infrastructure - segregated vs marked bike lanes

Hopefully I will be back to a more or less regular blog posting schedule now that I am back from my trip overseas. I went to Dublin (Ireland) and Edinburgh (Scotland) for a few weeks of vacation and a couple days of conferencing.  I was lucky enough to get to do some biking both inside and outside of the city (the city being Edinburgh). Today’s post is more of a reflection on biking culture and infrastructure in Ireland and Scotland versus here in Canada. I was only there for a short while so I am sure locals will have much more insight than I; don’t be afraid to let me know if I’ve got something wrong.

Both Dublin and Edinburgh appear to make extensive use of on-street bike lanes. These are generally shared with bus lanes and are often painted red, which makes them impossible to miss by motorists. I noticed continuity of markings and signage (i.e. I as a cyclist knew where I was supposed to be at most times) and priority for cyclists (e.g. areas allocated for cyclists in front of motorists at intersections – see picture below).  Bike lanes also continued on more rural roads, along with pedestrian islands to slow traffic, which you don’t see here in Canada. Even though streets were busy and I had to ride on the opposite side of the road I did not feel scared to be on the road, perhaps because motorists are more cyclist-savvy and no one yells or honks at you.   

On-street marked bike lanes in Dublin, Ireland

The infrastructure in these cities has made me wonder if on-street marked bike lanes are the way to go. Don’t get me wrong, I am not against segregated lanes, but on-street marked lanes would likely be cheaper, more direct, and make fewer people angry (e.g. merchants who lose parking spaces).  Changing our cycling culture requires, at the very least, making friends not enemies (I'll talk about this in an upcoming post). 

I’m just not sure if on-street marked lanes are safer for the average person and I doubt that parents would be more willing to let their children commute anywhere on them versus segregated lanes or a sidewalk.  At the same time, some segregated bike lanes can be dangerous because motorists can’t see you. For example, in Hull, there is a National Capital Commission off-road pathway that crosses three roundabouts; it is blocked to traffic by a wall until you have to cross each roundabout.  Motorists coming into and out of the roundabout are looking for other cars and often nothing else. Cyclists are quicker than pedestrians and may appear out of nowhere to motorists. I have had a few close calls. Being on the street makes you seen and forces motorists to more or less treat you like a car. This is why I cycle on the road in this area, even with motorists motioning to me in some sort of code that I think means I should be using the ‘perfectly good bike lane’ beside me.

I think therefore that a comparison of segregated and on-street marked bike lane safety is beside the point (the evidence shows that both may be beneficial compared to unmodified road ways, and that the sidewalk is the worst). I guess the appeal of segregated lanes is that they may induce feelings of safety, whether real or imagined which could motivate people to actively commute. My point is that we may want to investigate more wide-spread use of on-street marked bike lanes that are highly visible as in Dublin and Edinburgh, and/or with buffer zones as in New York City (see picture below), as these could improve both real and imagined safety in the same way, improve route directness, be more cost-effective, and piss fewer people off.    

 A buffer zone in NYC

Reynolds, C., Harris, M., Teschke, K., Cripton, P., & Winters, M. (2009). The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature Environmental Health, 8 (1) DOI: 10.1186/1476-069X-8-47

Some musings on sustainability and obesity: focusing on BOTH physical activity & diet needed

 

There is no disputing that diet and physical inactivity are contributors to the obesity epidemic. A recent debate involving Drs Yoni Freedhoff and Bob Ross showed that both are important (I don’t think there was consensus in the audience as to who won). What I want to highlight in this post is that, from a sustainability perspective (see my previous post for a definition), it is a moot point to argue over the relative importance of each.

Our food system has changed dramatically over the last few decades. We can get tasty, energy dense, often nutrient-poor foods anywhere, for very little money. And we’re constantly bombarded with advertisements to buy and eat these foods. What’s more is that we have almost completely engineered physical activity out of our daily life. For instance, most jobs nowadays require sitting for 8 hours (I am sitting as I write this), escalators and elevators do the climbing for us and are easily accessible, and we live far from where we work, play, or go to school so often must rely on the car, which involves more sitting.

I think there is a consensus developing among obesity researchers and health professionals that obesity (or diabetes or other related diseases) is not entirely the fault of the individual. In my opinion, unhealthy behaviours are a natural response to our “obesogenic” environment, which increase a person’s risk of developing obesity. So then why do we expect that prevention or treatment efforts targeted at the individual will be effective and maintained over the long-term? To fix our deranged food system and culture of sitting requires interventions at higher levels of social organization, including changes stemming from the local community, municipal, provincial, and national governments, as well as the global community.

In the last 10 years there has been a boom the number of scientific studies examining how our environments, beyond the household, are associated with obesity. The majority of these studies have been observational, with a cross-sectional design, and have looked at things like how street infrastructure, fast food restaurant density, and socioeconomic-level of residential neighbourhoods relate to obesity among adults.  Children have been less studied in this regard, as well as other types of environmental exposures, such as social interactions, and other types of areas, such as those around workplaces and schools (since these are likely not in one's residential neighbourhood).  Perhaps because of the complexity involved, even fewer studies have examined how specific policies and programs may influence physical activity, diet, and obesity at higher levels of social organization (you can find an example here).    

Certainly more studies are needed given the weaknesses in the current literature, as well as the dearth of information in some areas. But I would like to put forward another argument.  Increasing the “walkability” and “liveability” of our shared spaces - *may* decrease obesity but will likely help to decrease green house gas emissions. Making it easier for us to get and cook wholesome foods (namely fruits and veggies) that are free of pesticides, antibiotics, and other chemicals, and harder to get meat, as well as processed foods *could* decrease obesity, but could also help to reduce land degradation, pollution of our water sources, and climate change. All of these things are good for our health in ways other than on our waistline.       

My argument is that if there is a focus on sustainability, which these changes imply, population and environmental health should follow.  We need to focus on BOTH the diet and physical activity side in order to not only combat obesity, but a myriad of environmental problems and related health ailments like diabetes and asthma.  These changes are complex, don’t happen overnight, and may bring with them a whole set of new problems (the potential problem of denser living leading to a decrease in indoor air quality immediately comes to mind as an example). 

Nonetheless, I think we need to move towards rigorously implementing and evaluating interventions that increase sustainability – looking to see if they a) improve the environment, b) reduce obesity, or improve lifestyle behaviours, and c) that they do not negatively impact health in other ways (a post for another day).

Feng J, Glass TA, Curriero FC, Stewart WF, & Schwartz BS (2010). The built environment and obesity: a systematic review of the epidemiologic evidence. Health & place, 16 (2), 175-90 PMID: 19880341

Part 2 Building Design: Fooling people into taking the stairs

I just got back from a conference in Montreal – one on obesity at that. The hotel, the location for the conference, held sessions on floors 1-4 and on sub floors below the lobby – ample opportunity to use the stairs.  There were two main problems: 1) the stairs were confusing – you’d get up to one floor but then couldn’t find the next set of stairs to the next floor and have to walk quite a distance to get to them; and 2) there were escalators in between these floors in plain sight from the main floor lobby, somewhat easy to navigate, and were a brilliant, flashy gold colour. I, more often than not, took the flashy-fancy escalators. 

In my last post, I reflected on how easy it is to be physically inactive nowadays and went on to discuss point-of-decision prompts as a way to get people to use the stairs instead of escalators or elevators. These prompts appear promising, but what if buildings are not designed to make taking the stairs easier or enjoyable, such as was the case at the obesity conference? To answer this, in today’s post I will discuss the recommendations provided by New York City’s Active Design Guidelines to make buildings enjoyable places to walk – and some instances make walking the more convenient form of transportation. The guidelines were developed based on the best available evidence in the literature, as well as on current best practices in architecture and design. So keep in mind that even though these are recommendations there is no guarantee that they’ll work to increase physical activity.  At the same time however, they have direct synergies with sustainability, such as decreasing electricity and building material use (so, in my opinion, are at least worth considering).

There are three main categories of building design recommendations that I’ll touch on in my discussion below: 1) Elevators and escalators; 2) stairs; and 3) supportive design elements. I think that the more recommendations implemented, the more likely that building design will be successful at increasing the physical activity levels of its users.    

Design of elevators and escalators

Mechanized options for travel between floors should be designed to be hard to find, or at least less prominent (not the case for the escalators at my conference). Decreasing their speed can make them less efficient than walking, and save on electricity. Installing the minimum number of elevators required by building codes could also decrease efficiency by increasing volume of users. Other ways to make elevators less efficient than walking include programming them to:

• Be skip-stop (they don’t stop on every floor so you have to get out and walk up a floor);
• Open at each floor (this may not make sense in buildings with 30+ floors);
• Open and close very slowly (which is beneficial for persons with disabilities) 

Design of stairs

Stairs should be the main attraction. They should be visible from the lobby and elevators, and always located close to building occupants (i.e. office areas). One way to draw attention to them is to put the lobby of the building on the second floor, accessible from the ground floor via a grand staircase, with elevators accessible only at the lobby (meaning people have to use the stairs to access the elevators). Point-of-decision prompts can also help (as I discussed in Part I).  A great example of making stairs interesting -maybe a bit extreme and perhaps not sustainable, but cool nonetheless- is the piano stairs:  

Additionally, stairs should:

• Open to and be accessible at each floor (no locked doors);
• Be seen – if stairwells are a must they should be transparent;
• Receive large amounts of natural light;
• Be well ventilated

Canadian Museum of Nature, Ottawa (ON): CC images Michelle Hotchin

In order to improve the overall experience, stairs themselves should be designed for comfort, aesthetics, safety, and ease of maintenance. Art and articulated and unique stair composition can increase interest. Balustrades, handrails and landings can provide architectural points of interest, especially for grand staircases. Floor finishes should be slip resistant and colour or textural contrasts can be used to increase safety. Step height should be comfortable for small children (i.e. not too high), and staircases should be wide enough for groups traveling in opposite directions to safely pass. Finally, stairs should be easy to maintain. Long lasting materials should be chosen that are easy to clean and discourage vandalism or graffiti.   


   

Cooper Union New Academic Building, New York, NY: CC images

Supportive design elements

There are some things that can be included in building design that make being physically active easier and more enjoyable. Change rooms and showering facilities are big ones for me. My work building currently does not have one. I figured it would be quite easy to add a shower – one for men and one for women and no need for change rooms as our washrooms are so large. No dice though, my request was immediately shut down by my organization – citing no money. Always the excuse. I plan to press the issue. Bike parking and storage are also important. In NYC, several laws have been enacted that mandate certain buildings and facilities provide bicycle parking or other accommodation for cyclists. Storage can also prevent damage to building interiors when bikes are brought inside, and also prevent nasty notes from being sent to you when you forget your bike lock. 

Design of building exteriors should also have the pedestrian/cyclist in mind and interestingly can influence building users and non-users alike. Here are a few examples that can enliven, and improve the comfort/convenience and safety of the streetscape:

• Reducing set-backs (space between the road and building) and providing multiple entry points 
• Adding awnings or canopies (to provide shelter from the weather)  
• Porches, stoops, and terraces can add to the social environment and provide ‘eyes on the street’ 
• Paying attention to nearby parks, open spaces and public gathering areas so that the building does not adversely affect them (e.g. minimizing the cast of building’s shadow, and the potential for creating unpleasant wind conditions)

Building in New Orleans (LA): CC image

The design of public buildings (including point-of-choice prompts) has the potential to not only increase physical activity, but also to vastly improve the quality of our shared spaces. Perhaps residential spaces could also be designed to promote physical activity and reduce sedentary behaviour. The hard part is that people generally choose what they live in and where they live.  It is my hope that more and more researchers examine how design of our spaces (from houses to cities) may influence not only obesity but overall health, with high quality epidemiological methods - something that is currently lacking.              

Bloomberg MR, Burney D, Farley T, Sadik-Khan J, & Burden A (2010). Active Design Guidelines: Promoting Physical Activity and Health in Design City of New York

Part 1: Building design to increase physical activity

We all know that we are not getting enough physical activity these days. In fact, 52% of Canadian adults 20 years of age or older are considered inactive, and 88% of children aged 5-19 years don’t meet Canada’s physical activity guidelines. It’s one out of many reasons why the prevalence of overweight and obesity is so high. But physical activity has other health benefits, in addition to staving off obesity and cardiovascular disease, such as reducing stress and improving concentration, promoting correct physical growth in children, and maintaining mobility and independence in the elderly. 

The problem is that it’s just too easy to be physically inactive.  Our society has, for all intents and purposes, engineered physical activity out of the built environment – important, especially when you consider that schools and many jobs require us to be sitting for most of the day to begin with.  Take for instance stair climbing; it is a great means of increasing cardiovascular output, but the need for it has all been eliminated by the design of modern buildings.  Escalators and elevators are easy to access and do the work for us, but are energy guzzlers - elevators account for 3-10% of a building's energy uses. Stairs, our healthy and environmentally friendly benefactor, are difficult to find, often ugly and dark, and sometimes invite anti-social activity. It’s no wonder people don’t use them.

Can we design public buildings then to increase physical activity? This is a burgeoning area of research with evaluation studies still lacking. In the next post, I’ll discuss some recommendations made by the City of New York in their Active Design Guidelines, based on the best available evidence and best practices.  However, I’d like to discuss here point-of-decision prompts as a way to get people to use the stairs instead of escalators and/or elevators – a bit different than design per se but related and still very relevant and interesting.  I was actually pleasantly surprised to see that there was a large enough body of research to warrant a systematic review on the subject.

Motivational sign from Kino Québec (not sure why the guy is blue).  More info is available at: http://www.kino-quebec.qc.ca/marche/promotions.asp 

This very recent systematic review was published in the Scandinavian Journal of Public Health in 2010 and included 25 studies that examined the role of posters (n = 16), stair-rise banners (n = 5), both (n =4), or posters and floor graphics (n = 1) in helping people decide to take the stairs versus elevators (n = 8) or escalators( n = 18).  The majority of studies were conducted in public transit stations (e.g. train, bus, airport), shopping malls, or office buildings.  All used the interrupted time-series design (before-after where the ‘before’ sample does not necessarily contain the same individuals as the ‘after’ sample).               

Of the 42 comparisons (more than one comparison often conducted in a study), 31 reported modest but significant increases in stair climbing, 10 reported no association, and 1 reported an inverse association. The non-significant results were more likely to be reported by studies examining stairs versus elevators. There were no consistent differences between men and women. Of the significant studies that calculated odds ratios, those in favour of the intervention ranged from 1.05 – 2.93. Results appear promising with perhaps more work to be done to get people to use stairs instead of elevators versus escalators.  

Motivational sign from NYC Active Design Guidelines

There are some important things to keep in mind about this review and the included studies:

• Follow-up times were fairly short (at most 6 months). Some studies found that stair climbing decreased back to baseline over time (I guess as the novelty wore off)  
• I’m not certain as to how denominators were calculated at the ‘point-of-decision’. This was not discussed in the review but likely easy to find out by accessing individual articles  
• Only studies that looked at stair ascent were included. I think descent is equally important  
• It’s not readily apparent which messages and/or mediums work best 
• The same authors conducting different studies make up a large proportion of the included studies. This appears to happen in 4 instances and amounts to 16/25 studies.  This increases the likelihood of a bias occurring in one study being replicated in another, and both (or in some cases 6) being included in the review 
• Finally, as I alluded to earlier, the study designs are methodologically weak. The authors of the review recommend a control-site but comment on the difficulties of making this happen in practice.  In my opinion, stronger designs are more difficult in public transit buildings and malls – but feasible in office buildings (e.g. randomizing buildings and following the same people within each building). 

Point-of-decision prompts look like promising ways to get people to take the stairs (another review came to similar conclusions) but I think that more high quality research is warranted.  Additionally, what if point-of-decision prompts were accompanied by changes in actual building design? You’ll have to read my next post to find out. Stay tuned.

Nocon M, Muller-Riemenschneider F, Nitzschke K, & Willich SN (2010). Increasing physical activity with point-of-choice prompts -- a systematic review Scandinavian Journal of Public Health, 38, 633-38

Battle of the bike lanes - in NYC and now Ottawa-Gatineau?

Hat tip to Atif who brought this story to my attention this past November.  Over the last three years the Bloomberg administration has created over 200 miles of bike lanes and passed several bicycle friendly laws. This has been to the detriment of infrastructure supporting car use. To me, this is great news but to others that have a special attachment to their cars, or fear delivery trucks won’t be able to make their morning deliveries, this is terrible news. A similar story is starting to unfold in Ottawa; a ‘not-in-my-backyard’ mentality.

There is a war raging now in New York City – over bike lanes

In NYC, vocal opposition by drivers and elected officials has led to the removal of newly established bike lanes in Brooklyn and on Staten Island – lanes that communities originally wanted after extensive public consultation.  It seems that in the US, if you don’t agree with the government and don’t get your way, then you sue (if you have the means that is). That’s precisely what’s happening in New York City. A bike lane along Prospect Park West, a road forming the boundary between the Prospect Park and the well-to-do neighbourhood of Park Slope, is at the centre of a lawsuit brought on by wealthy, well-connected Brooklyn residents. According to the Times, almost three quarters of Park Slope residents are in favour of the bike lane; however this drops to 50% of residents who live along Prospect Park West, prime real-estate that overlooks the park.

A nice butt shot of me on one of NYC's off-road bike lanes

Opponents have cited many faults by the DOT - erroneous, misleading statistics, lack of transparency and public consultation, sub-par design, reduced room for cars, reduced safety, to name a few.  As reported by the Times, room for the legal complaint to be made stems from a state statute that allows challenges to government actions considered to be arbitrary or unfair. Nowhere do I see these two requirements being met by bike lane opponents. It just seems like a complaint against changing the status quo and making life slightly less convenient.

From an overall perspective, DOT statistics show that bicyclist fatalities and crashes in NYC have decreased almost 19% from 2006 to 2010, with the number of cyclists doubling from 2006-2010, and increasing 13% from 2009-2010. However, I did not come across stats on percentage of mode share (although this is likely premature as I discuss below). For Prospect Park specifically, DOT reports that crashes involving injuries are down 63%, speeding by cars is down from 75% to 20%, and cycling on the sidewalk is down 80%. Area residents and users of the lane also report feeling safer. Opponents, however, feel that the numbers have been deliberately 'fudged'. As reported by TransportationNation, the lawyer of the group filing the lawsuit stated:

“Everyone should be concerned about DOT’s misuse of the data. Everyone. This case is about a government agency wrongfully putting its thumb on the scale by fudging the data and colluding with lobbyists. That is not what ‘public integrity’ means. Some people on both sides of the issue are affluent and have political connections. So, the continuous, one-sided name-calling is hardly appropriate. But, more importantly, it keeps people from focusing on the real issue in the case, which I suspect is the true aim.”

Clearly an independent third party needs to evaluate use and safety of biking infrastructure if these statistics are to be believed. At the same time, new biking infrastructure will take some getting used to (by users and non-users alike) and time to increase awareness in the general NYC community (to increase the number of users), so an in-depth evaluation right away, in my mind, is premature. Additionally, it’s pretty hard to argue with people who think that a bike lane is a terrorist plot. I am truly amazed and saddened by this on-going saga. I mean they are bike lanes after all – meant to reduce congestion and greenhouse gas emissions, and increase safety for all…  

Some debris left in a NYC bike lane; Creative Commons Image  

Foreshadowing for Ottawa-Gatineau?

Certainly, the biking infrastructure in the Ottawa-Gatineau area is not quite as extensive and the proposed plan to create a segregated bike lane on Laurier Street has not generated nearly the level of disaccord; however, it’s there. Interestingly more lanes are planned; the National Capital Commission has quietly announced plans to implement a segregated bike lane on Wellington Street.

The idea of implementing biking infrastructure is to make cycling more enjoyable, safe, and convenient, and driving less convenient – ultimately, to change the commuting mode share.  

Complaints in NYC and in Ottawa have some commonalities

Why do all this for only a select few people? Only the hardiest of hardy cycle all the time and that’s not a lot, especially given our winters. Cycling will never catch on:

Well the point is to encourage MORE people to take their bikes instead of their cars. This will take time for people to switch and for infrastructure to keep up with demand. Biking in winter (as well as in the other three seasons) is possible if it becomes the norm – with dedicated bike lanes that are well-connected and maintained throughout all seasons (a colleague of mine has discussed Finland’s meticulously ploughed bike lanes in winter). 

Bike lanes take away parking spots for paying customers:

This is debatable. Cyclists take up much less space than cars and have easier access to stores and shops (along with public transit users). Thus, bike lanes with bike parking have the capacity to bring in more paying customers; previous estimates in Germany and the UK show that pedestrianised areas can increase the number of shoppers by 20-40%.  And an Australian study determined that each square metre of space allocated to cars contributed just $6/h in shopping expenditures, while each square metre of space allocated to bicycles brought in five times as much ($31/h).

A recent Globe & Mail article also highlighted the problem of traffic congestion and excessive commute times potentially affecting the economic performance of urban centres in Canada. The Toronto Board of Trade’s international city rankings on Prosperity, which measures cities on a number of economic, social and structural indicators, put only two Canadian cities in the top 10 overall (Calgary and Toronto); none cracked the top 12 for transportation. Clearly driving, which has the highest mode share in Canada, is not all that efficient.     

If you want more economic convincing, a writer at the Economist makes a good case for bike lanes (in NYC) ‘from an economic perspective;’ which is definitely worth a read.

Some final thoughts

I think that many people are aware that the design of our residential spaces (at least in North America) is not sustainable. By comparison, we are much more slowly piecing together how our commuting/convenience lifestyle may be at least partially to blame for our growing waistlines and associated chronic diseases. Many people say they would like to do something to change but when it comes down to it, they can’t sacrifice the convenience.  I think we all must be willing to try new things and accept some level of inconvenience if we are to put a halt to both environmental degradation and obesity.  At the same time, we need to measure the impacts of these changes to determine how we can do better, and that public money is spent wisely.  Cyclists need to do their part as well: respect pedestrians, the rules of the road, and not assume that pedestrians or motorists will behave in the right/legal/expected way. Finally, bike lanes are not a be all and end all of sustainable transit – the trick will be balancing the needs of all types of active (e.g. biking, walking, & rollerblading) and public (e.g. rail, tram, bus, etc.) transit modes while making driving less desirable.      

WHITEHEAD, T., SIMMONDS, D., & PRESTON, J. (2006). The effect of urban quality improvements on economic activity Journal of Environmental Management, 80 (1), 1-12 DOI: 10.1016/j.jenvman.2005.01.029

Lee, A., & March, A. (2010). Recognising the economic role of bikes: sharing parking in Lygon Street, Carlton Australian Planner, 47 (2), 85-93 DOI: 10.1080/07293681003767785

Is green good for our health?

Is being in a ‘green’ environment good for our health and well-being? Are we starved of this connection with nature? Richard Louv thinks so, author and chairman of the Children and Nature Network.  He has coined the term ‘nature-deficit disorder’ to reflect the psychological, physical and cognitive repercussions of our lack of contact with nature, especially among children in their vulnerable developing years.  Although Mr Louv specifies that this is not a formal diagnosis, I am not in love with the term because I find that it does bring forth this meaning to me. I admit that I haven’t yet read “Last Child in the Woods” (am planning to once the single copy on loan at UO has been brought back finally), but I wanted to investigate the scientific evidence for this idea a little further.  And then discuss, in the grand scheme of things, whether the evidence really matters anyway.

The Child and Nature Network has been busily compiling together the evidence base for nature and health.  While it is important for an advocacy group to do this, I find it somewhat biased from my perspective as an epidemiologist – where are the studies that examined these types of relationships but didn’t find anything? So like any good epidemiologist would do, I set out to look for some systematic reviews and meta-analyses.    

 

Without much looking I came across a recent systematic review that sought to examine studies that compared health outcomes in natural and synthetic environments, usually over a short duration. Twenty-five studies were included, with most being cross-over or controlled trials; although seven were randomized controlled trials. The most common outcomes were scores on various self-reported emotions. This is somewhat problematic in that respondents often can guess what is being studied (especially if it’s a non-randomized cross-over study) and will sometimes adjust their responses. More robust study designs (such as RCTs or at least randomizing order of exposure to each of the environments) can help to mitigate this bias. Other common outcomes included physiological measures such as cardiovascular functioning (blood pressure or pulse), and hormone levels (salivary or urinary cortisol, amylase, and adrenaline). Less common outcomes included immune function, physical activity, motor performance, cerebral brain activity, engagement, memory recall, and sleeping hours. There were too few of these to conduct a meta-analysis so I won’t discuss them further – you can get more info here.

The meta-analysis revealed (see Table 1 above) a possible benefit of natural versus synthetic environments for energy, anxiety, anger, fatigue and sadness. No benefit was seen for more objective measures like blood pressure and cortisol levels. There was a benefit reported for attention before effect sizes were adjusted for baseline levels. Because only 3 out of the 5 attention studies had baseline measures, this may have reduced statistical power, as the effect size decreased only slightly but the confidence interval increased.

Important points to keep in mind:  

·         Most of the included studies were experimental in design and included college students, adult males, or physically active adults – so the overall finding of the meta-analysis is not generalizable to the overall population, or to children 

·         Outcomes were examined over a very short duration. Some beneficial effects may take longer to manifest and/or require repeated or prolonged exposure to the natural environment

·         We’re not sure what exactly in the natural environment is responsible for these beneficial effects. Does this matter?

·         I am a little concerned with regard to the small number of studies, as well as study quality (this was not formally assessed). We may find a different association with a larger number of high quality studies

What does this all mean then? Over the short-term natural environments may reduce negative emotions and improve energy levels but they don’t appear to improve some cardiovascular and endocrine measures of health. Of course, I have to add the requisite last line: ‘more studies of high quality are needed,’ to make any definitive conclusions.         

Now from my own expertise and knowledge, I know that there have been more and more studies conducted to determine how the residential environment influences physical activity and/or obesity. This is a difficult area of research – perhaps why results have been mixed and effect sizes often small in comparison to the effects of individual and family characteristics. As I discussed in a previous post, some of these studies have found a positive association between the availability/amount of green space and the physical activity and obesity levels of area residents (in both adults and children). For the most part however, these have been cross-sectional associations, and overall, findings are not consistent from study to study. Putting this aside, we’re not even sure if it’s the greenery itself or simply the open space that invites people to be more physically active. Certainly greenery adds to the aesthetics and quality of the built environment, and aesthetics, as a general theme, has been previously associated with physical activity and obesity (see my previous post). Who knows though, we’d have to ask people why.       

In summary, the evidence of nature and health isn’t hugely convincing but not dismissive either – it’s there in some form. What we don’t know is whether it’s simply being active and away from our gadgets that helps the most – perhaps it’s not necessarily the ‘nature’ itself. Whether it’s the chicken or the egg doesn’t really matter to me and probably will never be totally discernible. As a society we are much more sedentary then in days gone by, and so it follows, less connected to nature. Green spaces can recycle the harmful outputs of urban living and add to the quality of our living spaces. To me, these two concepts go hand in hand. Paraphrasing a remark made by the artist Robert Bateman that was reiterated by Mr. Louv: if we don’t know about nature, we will be less likely to care for it and do something to preserve it. This is especially important among our children who will be the ones left to take care of the planet. Getting outside gets us physically active and connected to nature. So even though the evidence may not be sound, there is no harm in advancing this issue – it can only improve the quality of our spaces and help to sustain the world for future generations. Perhaps what is needed now are well conducted intervention studies to determine how green spaces can best be designed to maximize health, well-being, and sustainability benefits.  

Bowler DE, Buyung-Ali LM, Knight TM, & Pullin AS (2010). A systematic review of evidence for the added benefits to health of exposure to natural environments. BMC public health, 10 PMID: 20684754