And Vancouver is notable for its lack of freeways through the city. Just lots of big roads.
UBC study links living near highways to risk of neurological disorders
71–80 of 115 posts
Re: UBC study links living near highways to risk of neurological disorders
#72Earlier quoted context omitted.
As well as all cars with manual transmissions.
"Engine braking" isn't just letting the engine spin down at 0 throttle. Propper engine braking, aka "Jake brake", is letting the engine spin at 100% throttle but zero fuel input (and some valve trickery). This lets air in to be compressed, releasing it before the down stroke of the piston. No car does that. It is a separate installed system on trucks. It can be almost as powerful as the engine. In a car, it could han…
> Engine braking occurs when the retarding forces within an engine are used to slow down a motor vehicle, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes.
> The term is often confused with several other types of braking, most notably compression-release braking or "jake braking" which uses a different mechanism.
Re: UBC study links living near highways to risk of neurological disorders
#73Direct link to study: https://ehjournal.biomedcentral.com/articles/10.1186/s12940-... The researchers found the link between living near highways and future neurological disorders to be independent of income, education, ethnicity, comorbidity, and coexisting medical conditions associated with future neurological disorders (traumatic brain injury, diabetes, hypertension, stroke, coronary heart disease, congestive hear…
Re: Independent of income Living near a noisy highway is rarely prime real estate. How do we account forincome when there are so few in that subset? I also wouldn't discount the effect of endless stress. That is, the drone of noise. I recently moved from to a street that's fairly busy. Only in the middle of the night is it quite. I don't like it.
> Living near a noisy highway is rarely prime real estate. How do we account forincome when there are so few in that subset?
By comparing to those with low incomes who don’t live near the highway?
Re: UBC study links living near highways to risk of neurological disorders
#74Earlier quoted context omitted.
"Engine braking" isn't just letting the engine spin down at 0 throttle. Propper engine braking, aka "Jake brake", is letting the engine spin at 100% throttle but zero fuel input (and some valve trickery). This lets air in to be compressed, releasing it before the down stroke of the piston. No car does that. It is a separate installed system on trucks. It can be almost as powerful as the engine. In a car, it could han…
> Engine braking occurs when the retarding forces within an engine are used to slow down a motor vehicle, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes. > The term is often confused with several other types of braking, most notably compression-release braking or "jake braking" which uses a different mechanism. https://en.m.wikipedia.org/wiki/Engine_braking
But when you see a sign saying "no engine braking" it refers to the jake brake, not down-shifting in a car. (It's a long trademark story over the use of "jake")
Re: UBC study links living near highways to risk of neurological disorders
#75Direct link to study: https://ehjournal.biomedcentral.com/articles/10.1186/s12940-... The researchers found the link between living near highways and future neurological disorders to be independent of income, education, ethnicity, comorbidity, and coexisting medical conditions associated with future neurological disorders (traumatic brain injury, diabetes, hypertension, stroke, coronary heart disease, congestive hear…
Re: Independent of income Living near a noisy highway is rarely prime real estate. How do we account forincome when there are so few in that subset? I also wouldn't discount the effect of endless stress. That is, the drone of noise. I recently moved from to a street that's fairly busy. Only in the middle of the night is it quite. I don't like it.
It really depends on your building too. I live near a highway and getting around by car is really convenient as a result. Highway noise is not very audible due to the construction of the windows and the walls. My air quality meter says the PM1.0, PM2.5 & PM10 counts are 3-1 ug/m^3 inside and I don't have air filters on.
Re: UBC study links living near highways to risk of neurological disorders
#76Earlier quoted context omitted.
while switching to electric vehicles likely reduces break dust, such switch would simultaneously increase dust from tires, since increased acceleration. The latter being already 80% of urban "particulate matter" pollution.
Tyre wear does release particulate matter, but it's mostly heavy, large particles that end up on the road and get washed away by weather. With the exception of tunnels, where heavy particles are constantly being churned up from the road surface and re-circulated into the air, tyre and brake wear is a relatively minor contributor to urban air pollution.
> tyre and brake wear is a relatively minor contributor to urban air pollution
Why do you say that? Would love to know more, but all the research I've read lists them as significant contributors, second only to resuspension, each now exceeding tailpipe emissions on both PM 10 and PM 2.5.
https://www.sciencedirect.com/science/article/abs/pii/S13522...
https://dot.ca.gov/-/media/dot-media/programs/research-innov...
As an aside, we'd probably agree that vehicle weight is the mediating factor across all of these sources, regardless of the ratios from one type to the other. Massive load hauling trucks are generating a disproportionate share of emissions of all types, this is not really about making sedans a little more efficient.
Re: UBC study links living near highways to risk of neurological disorders
#77Direct link to study: https://ehjournal.biomedcentral.com/articles/10.1186/s12940-... The researchers found the link between living near highways and future neurological disorders to be independent of income, education, ethnicity, comorbidity, and coexisting medical conditions associated with future neurological disorders (traumatic brain injury, diabetes, hypertension, stroke, coronary heart disease, congestive hear…
If is very, very, very difficult to control for all these factors. Apart from the data dredging problem, the difficulty of controlling for all confounding factors is what make so few association studies hold up when prospectively tested.
As a rough rule of thumb if the hazard ratio is not 3 or greater in an association study then it almost certainly won’t be replicated prospectively.
Re: UBC study links living near highways to risk of neurological disorders
#78Earlier quoted context omitted.
while switching to electric vehicles likely reduces break dust, such switch would simultaneously increase dust from tires, since increased acceleration. The latter being already 80% of urban "particulate matter" pollution.
And weight, presumably heavy vehicles wear through more rubber, and batteries are heavy.
Weight. This is so much about vehicle weight.
I think the heavier EVs hit a crossover point because of regenerative braking, but weight does set them back, that's one of the whole points of this study:
https://www.sciencedirect.com/science/article/abs/pii/S13522...
This is a curve though. We could almost simplify the problem and only look at what heavy trucks generate and ignore all the cars completely, it'd be a non-crazy approximation.
Re: UBC study links living near highways to risk of neurological disorders
#79Earlier quoted context omitted.
As well as all cars with manual transmissions.
"Engine braking" isn't just letting the engine spin down at 0 throttle. Propper engine braking, aka "Jake brake", is letting the engine spin at 100% throttle but zero fuel input (and some valve trickery). This lets air in to be compressed, releasing it before the down stroke of the piston. No car does that. It is a separate installed system on trucks. It can be almost as powerful as the engine. In a car, it could han…
I have on my manual 15-year old diesel bmw very much an engine brake. It breaks quite well compared to neutral which seems to like to go on forever, and actually indicates proper consumption.
On highways and motorways, I rarely need to use brake at all. Of course, being a sensible driver helps (in contrary to what many people expect from me when they see the car and expect yet another immature aggressive driver)
Re: UBC study links living near highways to risk of neurological disorders
#80Earlier quoted context omitted.
Switching to electric vehicles would reduce brake dust even more, because they use regenerative breaking to avoid using the break pads when possible.
A set of pads typically lasts about as long as a set of tires (at the very least they're within a factor of two of each other). Compare relative volumes of materials. Brake dust is always going to be a much smaller source of particulate matter in the air than tire dust. FWIW if the fumes/particulate from burning them are any indication tires are probably way nastier than brakes.
> Compare relative volumes of materials. Brake dust is always going to be a much smaller source of particulate matter in the air than tire dust.
It's not a fair comparison, because you don't wear through the entire tire material as extensively as a brake pad. Fortunately we don't have to back of the napkin this one, there's lots of research showing brakes are near peers or exceed tires in contribution to PM 2.5.
As to your second point that brake material might be less harmful -- there is some initial research on how composition mediates impact.
Aluminum, sulfate, nickel, arsenic, and silicon seem to have the strongest relations. Aluminum is a frequent abrasive in brake pads, they aren't merely contributing some form of benign 2.5.
I can't do a comparison, you might be right it's "less bad" than tires, which contain other heavy metals. But I do not think the research is powerful enough to precisely settle that question beyond the overwhelming academic consensus that both are bad and we should definitely try to reduce both.
https://www.greencarcongress.com/2019/07/20190714-nee.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3755878/
https://dot.ca.gov/-/media/dot-media/programs/research-innov...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4315878/#Sec6ti...