Monday, April 30, 2012

The Next Congestion Charge System for New York City?

New York congestion pricing 2012 version (Road pricing, Mar. 12, 2012)

Also discussed here: Details of Sam Schwartz’s “Fair Plan” and Other Orcutt+Komanoff Highlights (Ben Fried, Streetsblog, Mar. 7,2012)

And here: The mother of all traffic plans hits NYC (Daniel Massey, Crain’s New York Business, Mar. 21, 2012)

 Today we review an interesting proposal to address some of the issues in the failed 2008 plan to introduce congestion charges for New York City failed at the state level (although it was supported by the city’s public). One of the big factors was the lack of benefit to many from outside the city who would pay tolls- and this is where the main opposition was. The 2012 plan introduces a collections system that does not involve money, improvements to highways and flexible pricing according to demand rather than fixed.
 Many of the questions posed (with some answers) are the same ones that other cities considering road pricing need  to consider


Key Quotes:
 “2008 version The proposal was to introduce a cordon on the southern half of Manhatten between 0600-1800 weekdays for all traffic except buses, taxis/for-hire vehicles, emergency vehicles and vehicles of disabled motorists”

 “2012 proposal The principles he used to reform these tolls were to:
  • Apply market based pricing where congestion is severe and there are public transit alternatives;
  • Lower tolls where alternatives are poor and congestion is low”
“it would generate gross revenues of $1.69 billion all up, would cost $250 million per annum to operate (including covering East River bridge maintenance costs) leaving the rest for transport funding. “

 “The calculated benefits are time savings worth $3.5 billion per annum from reduced congestion arising from a 22% reduction in travel time on average in the CBD. There are no doubt other benefits from reduced emissions affecting public health”

 “the proposed cycle/pedestrian bridges are an excellent way of promoting what are, in the long run, rather low cost alternatives to the car”

  • How should changes in tolls be assessed? -If traffic regularly operates at lower speeds, it can justify an increase, if it operates at higher speeds, the opposite.
  • How will a dedicated fund be set up to comfort those paying the tolls? -an independent arms length board be appointed, separate from the MTA, which will assess proposals for the use of revenues from relevant public transportation bodies.
  • When will existing toll systems be transitioned to fully electronic free flow tolling? -The savings made in abolishing toll plazas and the congestion they create will be worthwhile
  • How can discounts/exemptions be contained?- calls for them assessed against some key principles around economic benefit, social equity, practicality, effect on enforcement and cost.
  • What future proofing should any system have?- flexible enough to cope with pricing that may vary at different times of day and different directions of travel.”
“Although Mr. Schwartz doesn't want the term congestion pricing associated with his plan..His plan addresses the reasons earlier attempts at charging for travel into Manhattan's central business district failed. He said the charges are not a tax, but a way to price travel fairly where there's congestion and good transit”
Enhanced by Zemanta

Friday, April 27, 2012

Turning Urban Highways into Parks for People

The Life and Death of Urban Highways ( 44 page pdf, Institute for Transportation and Development Policy and EMBARQ, Mar. 2012)

Also discussed here: Urban Highways Offer Cities New Opportunities for Revitalization (Erica Schlaikjer, The City Fix, Mar. 21, 2012)

 The report reviewed today summarizes the social, economic and environmental benefits that have resulted from the removal of urban highways in five cities: Portland, Oregon; San Francisco, California; Milwaukee, Wisconsin; Seoul, South Korea; and Bogotá, Colombia. Each city used the new urban space in different ways but it is clear that the assumptions that went into the vast expansion of urban highways during the 20th century have changed or are changing to meet the needs of the 21st. One observes that all Canadian cities except for one have a freeway through their centre. The one that doesn’t has been rated one of the world’s top cities in terms of quality of life and environmental benefits. Care to guess which one? (Vancouver)  
Key Quotes:

“While the following report is about urban highways, more importantly, it is about cities and people. It is about community vision and the leadership required in the twenty-first century to overcome the demolition, dislocation, and disconnection of neighborhoods caused by freeways in cities.” (Peter Park, former planning director of Milwaukee)

 “In the past fifty years, tens of thousands of miles of urban highways were built around the world…Today, some of the same urban highways that were built in that period are being torn down, buried at great expense, or changed into boulevards”

 “Freeways are simply the wrong design solution for cities..they rely on limited access to minimize interruptions and maximize flow.. [but] they create barriers that erode vitality.. during traffic peaks, freeways actually worsen congestion”

 “expressways eviscerate cities.” (Jane Jacobs, The Death and Life of Great American Cities, 1961)

 “After Seoul removed the Cheonggyecheon, the average price for apartments in the area rose by at least twenty-five percent, as compared to only a ten percent growth in neighborhoods further away”

 “In Portland, the removal of their expressway cleared the way for the creation of the Downtown Waterfront Urban Renewal Area in 1974 and the creation of a large new waterfront park. Land values in the area have increased 10.4 percent annually on average, from $466 million in 1974 to over $1.6 billion in 2008”

 “When San Francisco replaced their double-decked freeway with the street-level boulevard, the “Embarcadero,” they saw an increase in property values in the adjacent neighborhoods of 300 percent and a dramatic increase in development in the area” “Instead of constructing new urban highways, cities can consider:
  • managing existing capacity more effectively..congestion pricing and time of day pricing, parking policy to discourage unnecessary car trips
  • Investing in mass transit..reallocate highways construction funds to expand mass transit, revenues from pricing program can also fund transit expansion or improvement”
  • implementing land use policies that discourage sprawl..encourage infill development, providing high quality bicycling and walking facilities”
Enhanced by Zemanta

Wednesday, April 25, 2012

How Does San Francisco Price On-Street Parking?

A Meter So Expensive, It Creates Parking Spots (Michael Cooper and Jo Craven McGinty, New York Times, Mar. 15, 2012)

 San Francisco is a leader among cities which want to reduce the number of drivers circling the block for an open space and adding to the traffic congestion found in many downtown areas. It is doing this by adjusting the rates charged by parking meters up or down (by 25-50 cents/hr) every 2 months based on actual usage of each space in order to meet an optimum usage and revenue target. Higher rates, now capped at $6/hr are being slowly phased in. The benefits are several: reduced congestion, less pollution and more revenue to improve transit and last, but not least, anyone looking for a open parking space will find one.  
Key Quotes:

 “San Francisco installed parking sensors and new meters at roughly a quarter of its 26,800 metered spots to track when and where cars are parked”

“aims to make sure that there is always at least one empty parking spot available on every block that has meters…raises the price of parking on the city’s most crowded blocks and lowers it on its emptiest blocks— the most expensive spots have risen to $4.50 an hour, but could reach $6”

 “after the city gradually raised the price of parking to $4.50 an hour from $3.50, high-tech sensors embedded in the street showed that spots were available a little more often”

 “ also has cut prices at many of the garages and parking lots it manages, to lure cars off the street”

“the program would benefit many poor people, including the many San Franciscans who do not have cars, because all parking revenues are used for mass transit and any reduction in traffic will speed the buses many people here rely on”

“using a market-based system to price key parking spots is an elegant solution to this challenge with the added benefit of reducing traffic and pollution”
Enhanced by Zemanta

Monday, April 23, 2012

What are the Economics of Road Pricing and Congestion?

Does Traffic Congestion Reduce Employment Growth? (33 page pdf, Kent Hymely, Journal of Urban Economics, Sept. 17, 2008) 

Also discussed here: Congestion’s Impact on Urban Economies (Surface Transportation Innovations #101, Reason Foundation, March 2012) 

Today, we review a paper that examines what economic benefits result from the application of road tolls or congestion charges on commuting speed and, indirectly, on the economy as demonstrated in several different cities and through simulation modeling of travel times on highways with tolls. The conclusion is that road pricing results in much shorter travel times which vary according to the effectiveness of the pricing (e.g. 70-90% in Cambridge,UK, 30-50% in Stockholm and 14-21% in London, UK). The reduced commuting times in turn resulted in a 10-30% increase in employment growth. This economic benefit, on top of the environmental benefits of reduced pollution and health costs, needs to be considered by cities contemplating road pricing in the future.
Traffic congestion, Sao Paulo, Brazil

Key Quotes:

“The effective size of an urban region’s labor market is bounded by how long it takes to make a typical journey to work. When shorter travel times increase the size of the labor market by 10%, the productivity of the metro area increased by1.3%”

“In the United States, urban vehicle-miles traveled increased 91% between 1982 and 2003…freeway lane-miles only increased 41%..a rapid increase in congestion-related travel delay.. from 16 hours per driver in 1982 to 44 hours per driver in 2003”

 “Workers generate congestion by driving to and from work during peak travel periods; at the same time, congestion discourages employment growth by raising workers' reservation wages and increasing shipping costs for goods”

 “[Cambridge, England] ..a cordon toll of 90 pence would reduce travel delay within the charge area by 70-90%... [Washington D.C.] a comprehensive toll of seven cents per mile ….would increase speeds by 12% on the Beltway, reducing delays 37% during rush hour …..[London, UK] actual speeds increased 14-21% after the city introduced a $5 cordon toll..[Stockholm].. City of Stockholm reported reductions in travel delay of 30- 50%”

 “the increases in employment growth following road pricing that reduces congestion by 50% are 10-30% higher”
Enhanced by Zemanta

Friday, April 20, 2012

Respiratory Health Impacts from Exposure to Roadside Emissions

Association between proximity to major roads and sputum cell counts (6 page pdf, Julie Wallace, Liesel D’silva, John Brannan, Frederick E Hargreave, Pavlos Kanaroglou, and Parameswaran Nair, Can Respir J, January/February 2011)

 Today we review some research into respiratory health impacts from exposure to nearby roadside emissions in the highly industrialized City of Hamilton. Results indicate increased bronchitis and asthma even for people located1 km away from major roads and highways.

Key Quotes:

“Air pollution from vehicular traffic emissions is a serious health hazard with significant impact on public health
  • Ambient particulate matter and pollutants from automobiles such as carbon monoxide and nitrogen dioxide are associated with respiratory morbidity and mortality;
  • these effects may be greater among persons with pre-existing obstructive airway diseases such as asthma
  • Proximity to major roads and high-density traffic has been reported to be associated with higher rates of wheezing, atopy and respiratory symptoms, decline in lung function and increased health care use in children”
“To examine whether proximity to major roads or highways is associated with an increase in sputum neutrophils or eosinophils, and to evaluate the effect of proximity to roads on spirometry and exacerbations in patients with asthma”

“Patients living within 1000 m of highways showed an increased risk of bronchitis .. particularly neutrophilic bronchitis..;as well as an increased risk of an asthma diagnosis.. Patients living within 300 m of a major road were at increased risk for an asthma exacerbation …. and lower lung function, particularly in women”

“asthmatic patients who spent 2 h walking on streets exposed to diesel pollution demonstrated an acute (but nonsignificant) increase in neutrophils with no increase in eosinophils (9), and traffic police officers exhibited increased airway neutrophil inflammation”

“The spatial extent of impact for mobile pollution sources reviewed in the present study was on the order of 100 m to 400 m for elemental carbon or particulate matter mass concentration (excluding background concentration), 200 m to 500 m for nitrogen dioxide and 100 m to 300 m for ultrafine particle counts”
Enhanced by Zemanta

Wednesday, April 18, 2012

Secondary Organic Aerosols from Gasoline Powered Vehicles

Service Oriented Architecture  
Gasoline emissions dominate over diesel in formation of secondary organic aerosol mass (Roya Bahreini, Ann M. Middlebrook, Joost A de Gouw, Carsten Warneke, Michael K. Trainer, Charles A. Brock, Harald Stark, Steven S. S Brown, William P. P Dube, Jessica B. Gilman, katharine Hall, John S. S. Holloway, William C. Kuster, Anne E. Perring, Andre S.H. Prevot, Joshua Peter Schwarz, J. Ryan Spackman, Soenke Szidat, Nicolas L. Wagner, Rodney J. Weber, Peter Zotter, David D. D. Parrish, Abstract, Geophysical Research Letters, Feb. 26, 2012) 

Also discussed here: Gasoline Worse Than Diesel When It Comes to Some Types of Air Pollution (Science Daily, Mar. 2, 2012) 

Today, we review some research from Los Angeles that examines the contribution of diesel emissions to the formation of secondary organic aerosols (SOA), tiny particles that make up most of the aerosol component of urban air pollution and highly harmful to health. The authors concluded that diesels contribute next to nothing to the SOA. The result is that even greater attention has to be paid to reducing gasoline emissions, previously thought to be less serious a health threat than diesel emissions.  

Key Quotes: 

“organic compounds in both gasoline fuel and diesel engine exhaust can form secondary organic aerosol (SOA), the fractional contribution from gasoline and diesel exhaust emissions to ambient SOA in urban environments” 

“Diesel emissions in the LA Basin vary between weekdays and weekends, with 54% lower diesel emissions on weekends. Despite this difference in source contributions, in air masses with similar degrees of photochemical processing, formation of OA is the same on weekends and weekdays” 

“the contribution from diesel emissions to SOA formation is zero within our uncertainties” 

"The surprising result we found was that it wasn't diesel engines that were contributing the most to the organic aerosols in LA"
Enhanced by Zemanta

Monday, April 16, 2012

Assessing Air Quality near Major Roads in Ontario, Canada

Environmental Guide for Assessing and Mitigating the Air Quality Impacts and Greenhouse Gas Emissions of Provincial Transportation Projects (78 page pdf, Environmental Policy Office, Ontario Ministry of Transportation, Jan. 2012)

Also discussed here: Air Quality and Greenhouse Gas Impacts of Transportation (Dianne Saxe, Envirolaw, Mar. 1, 2012)

Although it is considered still a “draft”, the guide reviewed today for assessing air quality and greenhouse gas emissions near roads in the province of Ontario is a major step forward. It defines when roadside vehicle emissions need to be dealt with and what standards or models should be applied. It is clear that many of the criteria take into account health impacts, such as the flagging of transportation projects where residences, schools, day cares, etc are located within 100-500 m of major roads and highways.
Key Quotes:

“MTO, as a proponent of provincial transportation initiatives, is responsible for addressing the air quality and climate change/greenhouse gas (CC/GHG) emission impacts of proposed transportation projects.. The majority of MTO’s transportation planning and design projects are subject to the Ontario and Canadian Environmental Assessment Acts. They involve new facilities or improvements to existing facilities”

“MTO provides MOE with supporting documentation so as to satisfy MOE that there is:
  1. a relatively small increase in the number of emission sources (i.e., vehicles and/ or traffic capacity); and
  2. sufficient distance from the edge of the highway right-of-way to sensitive receptors (e.g., residential dwellings and institutional buildings).
“For the preferred alternative and the planning timeframe (typically, 20 years): Assess local air quality impacts and, specifically, the likelihood, extent and duration of exceeding provincial ambient air quality criteria and national air quality standards.….The word ‘local’ refers to the immediate vicinity of the transportation system where the concentration of transportation-related air pollutants may exceed the ambient air quality criteria for one or more hours in a typical year”

For major roads, the collective experience of the scientific community suggests that the affected immediate vicinity is limited to the area within approximately 500 m of the road

 “The Guide uses a critical path methodology, focussed on whether the NOx or PM2.5 or greenhouse gas emissions of the proposed project would > 0.1% of provincial total..”

Road traffic on a typical 16 km (10 mile) portion of a four-lane highway produces more than, but not much more than, 0.1% of Ontario’s NOx and PM2.5 emissions. Hence, a 0.1% “screen” will capture any transportation alternative with emissions exceeding those of a 16 km (10 mile), four-lane highway.”

“During planning, the project team may have the opportunity to keep the distance of the highway or other major transportation facilities from sensitive receptors (residences) and critical receptors (hospitals, retirement homes, childcare centres, etc.), at approximately 100 m or greater”

“PM2.5 concentrations may exceed the 24-hour CWS of 30 g/m3 on a number of days in a typical year when highly unfavourable meteorological conditions persist. Exceedances are, however, limited to PM2.5 and PM10 and to locations within 100 m from the edge of highways”

“At very short range (30 m or less), large highway traffic volumes (over 100,000 vehicles per day) can contribute typically 80% of the ambient PM2.5 concentrations. This fraction drops to approximately 50% at 100 m from the edge of the highway”

Road pricing through electronic tolling or other means may result in a net reduction of total vehicle kilometres travelled and emissions generated in the region. The potential of this measure will, in part, depend on the availability of alternatives to the corridor and can be estimated with transportation demand models. Note: This measure is only applicable to new highways”
Enhanced by Zemanta

Friday, April 13, 2012

A Plan to Reduce Greenhouse Gases for Canada’s Capital

An Energy & Emissions Plan for Canada’s Capital Region (78 page pdf, City of Ottawa, City of Gatineau, National Capital Commission, Lead Consultant, HB Lanarc Consultants Ltd., Feb. 2012)

Also discussed here:Talking Points for Presentation to Environment Committee on Choosing Our Future(2 page pdf, Bill Pugsley, Feb. 21, 2012)
Today, we review the plans for mitigating Climate Change over the next 40 years, developed by the cities of Ottawa and Gatineau that make up the National Capital Region of Canada. While the largest contributor to greenhouse gas emissions is from heating and cooling and energy for buildings, the largest emission increases come from transportation and commuting by private vehicles in this urban area, one of the country’s cities at over 2,700 km2 (for Ottawa). Using best practices, emissions could be reduced by 27% from transportation, 95% from electricity and 100% from waste to meet the long term goal of 80% reductions by 2060. A number of potential targets for transportation, buildings, energy and waste are included. We look forward to a year by year funded action plan by each of the three jurisdictions (two cities, two provincial governments, and the federal government) to reach these targets.

Key Quotes:

“Under the best practice future residents and businesses could avoid a doubling in energy spending, saving $2.5 billion annually. By 2060, emissions in core community sectors would be 40% below 2007 levels. Early action could drive a 20% reduction in emissions by 2020”

 “the major community sectors over which municipalities have greatest influence: Land Use; Transportation; Buildings; Energy Supply; and Solid Waste

“the fastest growing energy sector is transportation. Transportation accounts for roughly one-quarter of energy use in the Region”

“the Province has committed to reducing GHGs by 6% from 1990 levels by 2014, 15% by 2020 and 80% by 2050.”

“emissions from transportation are estimated to decrease 27% by 2060 using Best Practices. This is due to a combination of higher vehicle efficiency and more non-automobile transportation (public transit, walking, cycling) supported by better infrastructure, and shorter travel distances due to land use changes”

“The Ontario government has set a target of one out of every 20 vehicles to be electrically powered by 2020. .. encourage or require new multi-unit residential and commercial buildings to provide charging facilities for battery-electric and plug-in hybrid vehicles”

“Emissions from electricity generation and consumption in Ottawa are expected to decrease dramatically, dropping by more than 50% by 2020 and nearly 95% by 2060 when compared to 2007 levels”

“Landfilled waste and greenhouse gases from waste would be almost eliminated by 2060 if best practices were adopted.. A key part of the strategy could be to focus on the virtual elimination of organics from landfills”
Enhanced by Zemanta

Wednesday, April 11, 2012

Slight Decreases in Air Quality and Higher Risk of Strokes

Ambient Air Pollution and the Risk of Acute Ischemic Stroke (Abstract, Gregory A. Wellenius, Mary R. Burger, Brent A. Coull, Joel Schwartz, Helen H. Suh, ScD; Petros Koutrakis, Gottfried Schlaug, Diane R. Gold, Murray A. Mittleman, Arch Intern Med., Feb. 13, 2012)

Also discussed here:  Even Moderate Air Pollution Can Raise Stroke Risks (Science Daily,Feb. 13, 2012)

Also here: Air pollution may increase stroke, heart attack risk (Anne Harding, CNN Health, Feb. 15, 2012)

Today, we review research that looked at the increased risk of short term exposure to slightly higher levels of air pollution (i.e. “moderate” compared to “good”), measured at hourly intervals. Results indicated that the onset of stroke occurs within 12-14 hours and that the most hazardous type of pollution (NO2 and PM2.5)comes from vehicles and traffic.

Key Quotes:

"The link between increased stroke risk and these particulates can be observed within hours of exposure and are most strongly associated with pollution from local or transported traffic emissions"

“Harvard's hourly measurements of pollution within 13 miles of 90 percent of the stroke patients' homes allowed for close matching in time of exposure and stroke onset…The increase in risk was greatest within 12 to 14 hours of exposure to PM2.5”

“days of moderate air quality substantially elevate stroke risk compared to days of good air quality..These results suggest that exposure to PM2.5 levels considered generally safe by the US EPA increase the risk of ischemic stroke onset within hours of exposure”

“reducing PM2.5 pollution by about 20 percent could have prevented 6,100 of the 184,000 stroke hospitalizations in the northeastern United States in 2007”

“black carbon and nitrogen dioxide, two pollutants associated with vehicle traffic, were closely linked with stroke risk, suggesting that pollution from cars and trucks may be particularly important”

"Any proposed changes in regulated pollution levels must consider the impact of lower levels on public health."
Enhanced by Zemanta

Monday, April 9, 2012

Car Addiction and Climate Change Mitigation

Se below
Se below (Photo credit: Wikipedia)
The implications of climate change for the future of the car (64 page pdf, Dr. Mayer Hillman, World Transport Policy and Practice, pages 18-29, Jan. 2012) 

Today we review a thoughtful article and the need to stabilize climate change by reducing carbon fuel use, in the context of a global look at the future for the personal vehicle. The author concludes that the only approach likely to take effect in the short time remaining is one based on capping carbon emissions globally on a per capita basis. The alternative is to run out of oil in less than four decades, not just for cars but for all the other uses. 

Key Quotes: 

“Catering for the seemingly never-ending growth in demand for the energy-intensive transport activities, especially car and air travel, has led to investment in more road building, airport expansion and improved rail transport” 

“UK passenger mileages by road, rail and air in the last 20 years have risen by 25, 65 and 160 per cent respectively” 

“global energy consumption will rise faster than ever, with more than a 50 per cent increase by 2035” 

“Current efforts to enable the car to continue to be the mainstay of personal travel .. more energy-efficient vehicles enabling less fuel to be needed; to encouraging car sharing and car clubs;economical ways of driving; and research on alternative fuels such as electricity generated from shale gas and bioenergy…. carbon emissions from the transport sector overall are still rising alarmingly”  

it is judged perfectly reasonable to decide where and how to travel entirely from a self interest perspective and with little regard to the effects on other people's quality of life on community health and on the physical environment, not least, on accelerating climate change” 

“it is not possible to respond sufficiently effectively to climate change in the absence of a world agreement. Based on the principles of precaution and equity set out in the United Nations Framework Convention on Climate Change, this is the Global Commons Institute’s (GCI) proposal.. It requires the imposition of a global cap on greenhouse gases and, given the finite capacity of the planet to safely absorb further gases and share them on an equal per capita basis between the world’s populations” 

“The process will act in a way that encourages individuals to adopt green practices far more effectively than they would through regulation, pricing, exhortation or appeals to conscience”
Enhanced by Zemanta

Friday, April 6, 2012

Monitoring Pollution from Downtown Construction and from Traffic in a Large City

Air Quality Monitoring Study of Construction Activities between 69th and 87th Street on Second Avenue (22 page pdf, Parsons Brinkerhoff, MTA Capital Construction, Jan. 17, 2012)

Today we review an interesting study from New York City, where health concerns about dust from road construction were addressed by an assessment of air quality by roadside monitors . Results indicate that the levels of high pollution on 3-6 days of the month monitored were due to traffic and not from blasting or other construction activities.  

Key Quotes:  
the dust generated by underground blasting operations for the excavation of the station caverns has contributed to visible sources of construction dust. Concerns over the potential health effect on the adjacent public of these dust particles and other pollutant emissions that could result from construction triggered the need for this air monitoring study”

The monitoring results for PM10 (i.e., coarse particles) indicate that daily (24-hour average) levels were lower than the PM10 reference level of 150 ug/m3, with weekday levels ranging from 15 to 60 ug/m3, and weekend levels from 5 to 40 ug/m3”  

daily PM2.5 concentrations were primarily attributed to local traffic emissions, other local sources such as commercial and residential boilers, and regional or background levels, with no significant contribution from blasting activities.”

“Of the gaseous pollutants, SO2 levels exceeded the reference levels on six different days”
Enhanced by Zemanta

Wednesday, April 4, 2012

Vehicle Emissions at Modern Roundabouts and Signalized Intersections

Quantitatively Determining the Emissions Reduction Benefits of the Replacement of a Signalized Intersection by a Roundabout (16 page pdf, Maxine Hesch, Academy of the Holy Names, New York State Dept of Transportation, March 2007)

Also discussed here: Impact of Modern Roundabouts on Vehicular Emissions (10 page pdf, Srinivas Mandavilli, Eugene R. Russell, Margaret J. Rys, Proceedings of the 2003 Mid-Continent Transportation Research Symposium, Ames, Iowa, August 2003)

Today we review two studies that examine the impact of modern roundabouts on reducing vehicle emissions compared to an intersection with traffic lights. Results indicate reduced Carbon Dioxide, Carbon Monoxide and Nitrogen Oxide emissions of about 26% with up to 50-60% reductions at peak traffic flow times.  
Key Quotes:
 “When vehicles are idle in a queue they emit about 7 times as much carbon monoxide (CO) as vehicles traveling at 10 mph. The emissions from a stopped vehicle are about 4.5 times greater than a vehicle moving at 5 MPH” “In another study Sweden, .. replacing a signalized intersection with a roundabout resulted in an average decrease in CO emissions by 29 percent and NOx emissions by 21 percent and fuel consumption by 28 percent per car within the influence of the junction”

“there are significant reductions from the roundabout for all parameters, ranging from a 16.36% reduction in nitrous oxide to a 26.05% reduction in hydrocarbons compared to the traffic signal“

“At its peak hour, the roundabout reduces carbon monoxide at the intersection by 8.5 kg/h. Peak hour …is generally regarded to represent about 1/10th of the daily volume. That makes the daily reduction of CO approximately 85 kg/day”

“a signal which meets design criteria will produce up to 26.05% more emissions than a roundabout at the same location“

“The average Carbon Dioxide (CO2) emissions (Kg/hr) for the intersection locations studied are 16 percent and 59 percent less for the AM period and PM periods respectively for the case of a modern roundabout”

“The average Oxides of Nitrogen (Nox) emissions (Kg/hr) for the intersection locations studied are 20 percent and 48 percent less for the AM period and PM periods respectively for the case of a modern roundabout”
Enhanced by Zemanta

Monday, April 2, 2012

Canadian Health Impacts to Long-Term Exposure to Fine Particulate Matter

Risk of Non-accidental and Cardiovascular Mortality in Relation to Long-term Exposure to Low Concentrations of Fine Particulate Matter: A Canadian National-level Cohort Study (29 page pdf, Dan L. Crouse, Paul A. Peters, Aaron van Donkelaar,Mark S. Goldberg, Paul J.Villeneuve, Orly Brion, Saeeda Khan, Dominic Odwa Atari, Michael Jerrett, C. Arden Pope III, Michael Brauer, Jeffrey R. Brook, Randall V. Martin, David Stieb, Richard T. Burnett, Environ Health Perspect, Feb.7, 2012) Today, we review a study that assesses the mortality health risk for native born Canadians from long term exposure to fine particulate matter which is higher in the Montreal-Ottawa-Toronto-Windsor corridor than elsewhere in the country. The authors concluded that there is a 31% increased risk of ischemic heart disease with an increase of 10 μg/m3 increase in PM2.5, a higher increase in health risk than previously estimated (12-14%). Key Quotes: “A systematic review of the association between long-term exposure to ambient pollution and chronic diseases conducted by Chen et al. (2008) concluded that long-term exposure to PM2.5 increases the risk of cardiovascular mortality by approximately 12-14% per increase of 10- μg/m3, independent of age, sex, and geographic region” “This is one of the largest cohort studies, and the first national-level Canadian study, to evaluate the risk of mortality associated with long-term exposure to PM2.5” “concentrations of PM2.5 were highest in urban areas, along the corridor between Windsor and Quebec City, and in the prairies of southern Saskatchewan and Alberta” “We found positive and statistically significant associations between non-accidental mortality and estimates of PM2.5 generated from both satellite-derived and ground-based observations in a large cohort of non-immigrant Canadians 25 years of age and older” “we estimated increased risks of mortality of 15% ..from non-accidental causes and 31%.. from ischemic heart disease for each 10-μg/m3 increase in concentrations of PM2.5
Enhanced by Zemanta