‘Bike boulevards’ can get Baltimore rolling

Summary:
Bike Boulevards, while useful, make no difference in biker exposure to particulate pollution, and we should stick to facts about barriers to biking.

reposted from my reply to the author:

Jeremy,

I absolutely agree with you, it would be great if more people bike to work and it would be nice to have more bike boulvards like guilford. Biking is good for our health and good for our society,

but did you do any research to back up this whopper?

"Bikers can significantly reduce their air pollution exposure by choosing a smarter, less traffic-filled route (Guilford), and avoiding busy streets (St. Paul and Charles)."

Since the pollution you are advising people to avoid is "increases(d) exposure to the invisible dangers of inhaled fine and ultrafine particles." I suggest you familiarize yourself with the research before you offer health advice.

Fines and ultrafines (pm <10um and <2.5um) are suspended particulates that do not drop off in concentrations until one is 20-50 m away from roadways, and that is only if the micro-climate is static (no winds). It is known that small particulate air pollution stays suspended in the air column until precipitation washes it out (hence suspended particulates). Within an urban environment scientists have long since learned the microclimate patterns are too complex to reliably estimate individuals exposure from stationary measurements. Personal monitors or fixed position monitors 30 meters from the nearest structure are the only reliable ways to measure particulate concentrations, and fixed monitors are even then a poor surrogate for individual exposure.

So for you to advise people on exactly which street to bike based solely on your subjective opinion of traffic density extrapolated (erroneously) to supposed future reductions in personal particulate exposure and thus health improvements assumes 4 things: 1. that lower traffic on guilford reduces fines and ultrafines emissions; 2. that concentrations are lower on guilford than st-paul ; 3 that biking on guilford will appreciably reduce peoples exposure to fines and ultrafines; 4 that this reduction in exposure will positively impact their health.

Assumption one is false. Ultrafine vehicle emissions are closely tied to vehicle type, and engine maintenance, to the tune of orders of magnitude of difference. One model year to the next can drastically change ultrafine emissions. Older vehicles and diesels tend to have high particulate emissions, but not predictably so for fines and ultrafines, and in the case of diesels the two can go in opposite directions. So unless you can prove that the traffic mix is identical but lower on guilford it may very well be that higher emission vehicles use guilford over st paul…or visa versa. But really this doesn’t matter because…

Assumption two is false. Over any stretch of street that folks will be biking the average particulate concentrations on adjacent streets are identical due to mixing. Adjacency or proximity to sources of pollutants only affects exposure when the pollutant is not long-lived or well mixed. This is why freon is everyones problem, or mercury. They live long enough to circle the globe several times over (mix) and affect everyone, regardless of source. Its the same principle but on a smaller scale in urban atmospheres. If there were a rain curtain or wall of dense greenery 100-200 feet high between StPaul and guilford (with extremely high surface area that slowed local winds to a standstill and act as a filter) then maybe….but all we have is moderate sized smooth surfaces (buildings) that accelerate ground level mixing and convection (hence the high cross winds at intersections and the occasional wind tunnel effect mid-block, next to corners or large buildings).

Assumption three is false. Studies show that where you live and where you work have the biggest impact on your pollutant exposure, because you spend the most of your time there. Air intakes in homes and business do not appreciably screen out ultrafines. In-fact diurnal patterns in ultrafines inside of office buildings are identical to and concentrations mirror exterior concentrations, and exposure to certain models of lazer-jet printers can actually substantially increase fine and ultrafine exposures in office environments. Since the folks you are reaching out to to bike Guilford live in the city and are commuting to somewhere else in the city, and since the city’s particulate pollution is fairly well mixed, most of those peoples exposure is allready determined, by the amount and type of traffic in the city at large and whether or not its raining or snowing. They would be spending at most 45 min a day on guilford vs st.paul, whereas they continue to be exposed to the city’s particulate pollution most of the rest of the day and the rest of their lives. Even if there is some minor difference in particle concentrations st.paul vs guilford, the rest of their exposure swamps any change from one street to the next.

Assumption four is false. If we suspend what we know about particulates (no pun intended) and assume there is some difference (albeit minor) in particulate exposure between st paul and guilford, this does not likely transform even 10x/week trips down the corridor into improved health. Again larger aggregate exposure will likely swamp the differences in exposure on these two streets, but more so, the major negative health effects of mid-to-low-level particulate exposure are chronic health effects, requiring a lifetime of exposure. Any meaningful change in someones health due to particulate exposure requires a decade or more of constant exposure to measureable differences in particulate concentrations. People would have to switch from st paul to guilford every day for the rest of their natural life and live and work in hermetically sealed and filtered environments with no other sources for these hypothetical differences to make a difference on a single persons health. Yes there are sensitive folks who, when exposed to particularly high particle & ozone concentrations concurrently, can experience acute respiratory and cardiac distress, but those are not the folks who are going to bike this corridor at all….nor should they until(if) their base health status improves.

I absolutely agree with you, it would be great if more people bike to work and it would be nice to have more bike boulvards like guilford. Biking is good for our health and good for our society.
But their are real risks from biking in baltimore (injury and death from crashes with objects and cars), and big barriers are things that the best bike boulvard networks only begin to address.

When police officers dont enforce traffic laws, when over 200 people kill each other in the city each year, when our bike and pedestrian fatality and injury rates are the 4th highest in the nation, when officers cant even be bothered to write reports on bike or pedestrian involved accidents, then the main barriers to a meaningful % of the population biking are not designating lower traffic roads as boulevards and adding signage and curbage, they are psychological aversions rooted in real hazards arising from behavioral patterns.

Until we change the behavior of people when they get behind the wheel in baltimore, until the population becomes convinced that traffic laws will be enforced and if someone else drives carelessly that they will be stopped, until they feel like the police are competent and "have their backs", until residents feel secure enough in their homes, streets, and lives that they care about following traffic laws, that they have enough money to buy and maintain bikes, then the biggest barriers will remain. And the % of the population biking will remain at the barely alive pulse that it is…less than 3 out of 2000 residents, and it will break down along risk tolerance and desperation lines: almost exclusively male, mostly white, some latino, a vast under-representation of the african-american community, mostly between 18 and 34 yo.

Additionally your referencing Baltimore’s ranking among "major cities" in % bike/walk commuters is re-iterating bad stats. When your sample size (cities over 500k) is small (<50) and when you rank, relative abundance data is lost and ranking can mask & exagerate differences. Additionally the ranks conflate biking and walking…which do not correspond with bike boulevards and your particulate pollution issues (ie biking is not the same as walking). Biking gets us meaningful distances in urban and suburban environments, walking only does that in very small, very specific, very dense urban cores. So biking is a better measure of transport for a majority of this population because it actually might lead to exercise as replacement for vehicle trips….whereas walking will only do that for a handful of people on a block or two of a few neighborhoods that have somehow retained the right mix of amenities. Furthermore, there are lots of smaller cities (>50k, >100k) that kick baltimore’s ass when it comes to the % biking (& walking). Saying we are doing well when we clearly are not just undermines the need for change among the skeptical…and the skeptical outnumber the faithful in baltimore 10:1 (or rather 2000:3).

I hate to be pessimistic, but poor research and over-promising only make an extremely dire situation worse when expectations are not met and bitterness sets in.
We don’t need amateurish booster-ism masquerading as science, and while particulate exposure is part the risk benefit health balance of biking, bike boulavards dont change this (short of replacement of sources ie single occupant vehicles replaced by bicyclists).

Nothing in your article addresses the barriers to taking up a bike when you have a car, or more importantly in this city, when all you have is a bus pass.

Best of luck on your degree.

2 Replies to “‘Bike boulevards’ can get Baltimore rolling”

Anonymous says:

February 9, 2012 at 9:54 am

Summary:
Bike Boulevards, while useful, make no difference in biker exposure to particulate pollution, and we should stick to facts about barriers to biking.

reposted from my reply to the author:

Jeremy,

I absolutely agree with you, it would be great if more people bike to work and it would be nice to have more bike boulvards like guilford. Biking is good for our health and good for our society,

but did you do any research to back up this whopper?

"Bikers can significantly reduce their air pollution exposure by choosing a smarter, less traffic-filled route (Guilford), and avoiding busy streets (St. Paul and Charles)."

Since the pollution you are advising people to avoid is "increases(d) exposure to the invisible dangers of inhaled fine and ultrafine particles." I suggest you familiarize yourself with the research before you offer health advice.

Fines and ultrafines (pm <10um and <2.5um) are suspended particulates that do not drop off in concentrations until one is 20-50 m away from roadways, and that is only if the micro-climate is static (no winds). It is known that small particulate air pollution stays suspended in the air column until precipitation washes it out (hence suspended particulates). Within an urban environment scientists have long since learned the microclimate patterns are too complex to reliably estimate individuals exposure from stationary measurements. Personal monitors or fixed position monitors 30 meters from the nearest structure are the only reliable ways to measure particulate concentrations, and fixed monitors are even then a poor surrogate for individual exposure.

So for you to advise people on exactly which street to bike based solely on your subjective opinion of traffic density extrapolated (erroneously) to supposed future reductions in personal particulate exposure and thus health improvements assumes 4 things: 1. that lower traffic on guilford reduces fines and ultrafines emissions; 2. that concentrations are lower on guilford than st-paul ; 3 that biking on guilford will appreciably reduce peoples exposure to fines and ultrafines; 4 that this reduction in exposure will positively impact their health.

Assumption one is false. Ultrafine vehicle emissions are closely tied to vehicle type, and engine maintenance, to the tune of orders of magnitude of difference. One model year to the next can drastically change ultrafine emissions. Older vehicles and diesels tend to have high particulate emissions, but not predictably so for fines and ultrafines, and in the case of diesels the two can go in opposite directions. So unless you can prove that the traffic mix is identical but lower on guilford it may very well be that higher emission vehicles use guilford over st paul…or visa versa. But really this doesn’t matter because…

Assumption two is false. Over any stretch of street that folks will be biking the average particulate concentrations on adjacent streets are identical due to mixing. Adjacency or proximity to sources of pollutants only affects exposure when the pollutant is not long-lived or well mixed. This is why freon is everyones problem, or mercury. They live long enough to circle the globe several times over (mix) and affect everyone, regardless of source. Its the same principle but on a smaller scale in urban atmospheres. If there were a rain curtain or wall of dense greenery 100-200 feet high between StPaul and guilford (with extremely high surface area that slowed local winds to a standstill and act as a filter) then maybe….but all we have is moderate sized smooth surfaces (buildings) that accelerate ground level mixing and convection (hence the high cross winds at intersections and the occasional wind tunnel effect mid-block, next to corners or large buildings).

Assumption three is false. Studies show that where you live and where you work have the biggest impact on your pollutant exposure, because you spend the most of your time there. Air intakes in homes and business do not appreciably screen out ultrafines. In-fact diurnal patterns in ultrafines inside of office buildings are identical to and concentrations mirror exterior concentrations, and exposure to certain models of lazer-jet printers can actually substantially increase fine and ultrafine exposures in office environments. Since the folks you are reaching out to to bike Guilford live in the city and are commuting to somewhere else in the city, and since the city’s particulate pollution is fairly well mixed, most of those peoples exposure is allready determined, by the amount and type of traffic in the city at large and whether or not its raining or snowing. They would be spending at most 45 min a day on guilford vs st.paul, whereas they continue to be exposed to the city’s particulate pollution most of the rest of the day and the rest of their lives. Even if there is some minor difference in particle concentrations st.paul vs guilford, the rest of their exposure swamps any change from one street to the next.

Assumption four is false. If we suspend what we know about particulates (no pun intended) and assume there is some difference (albeit minor) in particulate exposure between st paul and guilford, this does not likely transform even 10x/week trips down the corridor into improved health. Again larger aggregate exposure will likely swamp the differences in exposure on these two streets, but more so, the major negative health effects of mid-to-low-level particulate exposure are chronic health effects, requiring a lifetime of exposure. Any meaningful change in someones health due to particulate exposure requires a decade or more of constant exposure to measureable differences in particulate concentrations. People would have to switch from st paul to guilford every day for the rest of their natural life and live and work in hermetically sealed and filtered environments with no other sources for these hypothetical differences to make a difference on a single persons health. Yes there are sensitive folks who, when exposed to particularly high particle & ozone concentrations concurrently, can experience acute respiratory and cardiac distress, but those are not the folks who are going to bike this corridor at all….nor should they until(if) their base health status improves.

I absolutely agree with you, it would be great if more people bike to work and it would be nice to have more bike boulvards like guilford. Biking is good for our health and good for our society.
But their are real risks from biking in baltimore (injury and death from crashes with objects and cars), and big barriers are things that the best bike boulvard networks only begin to address.

When police officers dont enforce traffic laws, when over 200 people kill each other in the city each year, when our bike and pedestrian fatality and injury rates are the 4th highest in the nation, when officers cant even be bothered to write reports on bike or pedestrian involved accidents, then the main barriers to a meaningful % of the population biking are not designating lower traffic roads as boulevards and adding signage and curbage, they are psychological aversions rooted in real hazards arising from behavioral patterns.

Until we change the behavior of people when they get behind the wheel in baltimore, until the population becomes convinced that traffic laws will be enforced and if someone else drives carelessly that they will be stopped, until they feel like the police are competent and "have their backs", until residents feel secure enough in their homes, streets, and lives that they care about following traffic laws, that they have enough money to buy and maintain bikes, then the biggest barriers will remain. And the % of the population biking will remain at the barely alive pulse that it is…less than 3 out of 2000 residents, and it will break down along risk tolerance and desperation lines: almost exclusively male, mostly white, some latino, a vast under-representation of the african-american community, mostly between 18 and 34 yo.

Additionally your referencing Baltimore’s ranking among "major cities" in % bike/walk commuters is re-iterating bad stats. When your sample size (cities over 500k) is small (<50) and when you rank, relative abundance data is lost and ranking can mask & exagerate differences. Additionally the ranks conflate biking and walking…which do not correspond with bike boulevards and your particulate pollution issues (ie biking is not the same as walking). Biking gets us meaningful distances in urban and suburban environments, walking only does that in very small, very specific, very dense urban cores. So biking is a better measure of transport for a majority of this population because it actually might lead to exercise as replacement for vehicle trips….whereas walking will only do that for a handful of people on a block or two of a few neighborhoods that have somehow retained the right mix of amenities. Furthermore, there are lots of smaller cities (>50k, >100k) that kick baltimore’s ass when it comes to the % biking (& walking). Saying we are doing well when we clearly are not just undermines the need for change among the skeptical…and the skeptical outnumber the faithful in baltimore 10:1 (or rather 2000:3).

I hate to be pessimistic, but poor research and over-promising only make an extremely dire situation worse when expectations are not met and bitterness sets in.
We don’t need amateurish booster-ism masquerading as science, and while particulate exposure is part the risk benefit health balance of biking, bike boulavards dont change this (short of replacement of sources ie single occupant vehicles replaced by bicyclists).

Nothing in your article addresses the barriers to taking up a bike when you have a car, or more importantly in this city, when all you have is a bus pass.

Best of luck on your degree.

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B' Spokes says:

February 14, 2012 at 5:11 pm

Re: Since the pollution you are advising people to avoid is "increases(d) exposure to the invisible dangers of inhaled fine and ultrafine particles." I suggest you familiarize yourself with the research before you offer health advice.

I’ll suggest the same:
"A Dutch study has proved, yet again, that the level of dangerous microparticles are higher inside cars than on bikes."
https://www.baltimorespokes.org/article.php?story=20090625175040447

"RESULTS: Shifting 5% of vehicle kilometres to cycling would reduce vehicle travel by approximately 223 million kilometres each year, save about 22 million litres of fuel and reduce transport-related greenhouse emissions by 0.4%. The health effects would include about 116 deaths avoided annually as a result of increased physical activity, six fewer deaths due to local air pollution from vehicle emissions, and an additional five cyclist fatalities from road crashes. In economic terms, including only fatalities and using the NZ Ministry of Transport Value of a Statistical Life, the health effects of a 5% shift represent net savings of about $200 million per year."
https://www.baltimorespokes.org/article.php?story=20110328090709979

"Researchers at the University of Wisconsin were wondering if getting people out of their cars just a wee bit would create measurable improvements in health. health. So they gathered up data sets on obesity, health effects of pollution, and air pollution caused by automobiles in 11 Midwestern cities, and did a mashup."
https://www.baltimorespokes.org/article.php?story=2011110217155317

"They found that if the Midwesterners ran half of their short-distance errands by bike rather than by car, 1,100 deaths would be avoided each year, and $7 billion would be saved in reduced health-care costs. The trips were 2.5 miles one way; less than a 25-minute bike ride, the researchers figure."
https://www.baltimorespokes.org/article.php?story=2011110217155317

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Re: When police officers dont enforce traffic laws, …

Valid point for now but that should change as we get more out on bikes (we are showing progress on this so far.)

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