Hussein M.,University of British Columbia |
Popescu B.,University of British Columbia |
Sayed T.,University of British Columbia |
Kim L.,AKRF Inc
Transportation Research Record | Year: 2016
Automated computer vision video analysis techniques were used to analyze video data during the operation of New York City's Summer Streets Program at a major signalized intersection. The main objectives of this study were to diagnose pedestrian and cyclist safety issues during the shared space operation and to demonstrate the feasibility of the automatic extraction of road user data (e.g., pedestrian, runner, rollerblader, or cyclist) required for microscopic behavior analysis. Road users' speeds and pedestrian gait parameters (step frequency and step length) were automatically extracted and analyzed. Results show that pedestrian walking speed was highest during the Summer Streets operation (1.49 ± 0.54 m/s) because pedestrians had more street space to use and slowest during normal oper ations (1.30 ± 0.22 m/s). Bike speeds were low during the Summer Streets event (3.62 ± 0.97 m/s), likely because of interaction with pedestrians, but these speeds increased during normal traffic operations. Pedestrians and cyclists moving in groups tended to be slower and confirmed results found in previous studies. The safety analysis was conducted with traffic conflict techniques. It was observed that the lowest rate of conflicts between pedestrians and cyclists and between cyclists was found to be during Summer Streets operations. In addition, an analysis of spatial violations showed that some road users were not observing traffic rules in the transition period after Summer Streets ceased to operate.
McGarity E.,Swarthmore College |
Szalay S.,AKRF Inc. |
Cohen J.,Swarthmore College
World Environmental And Water Resources Congress 2016: Water, Wastewater, and Stormwater and Urban Watershed Symposium - Papers from Sessions of the Proceedings of the 2016 World Environmental and Water Resources Congress | Year: 2016
Municipalities are turning to green infrastructure (GI) as an attractive solution for combined sewer overflow (CSO) control. Given the myriad combinations of GI implementation options, decision makers need tools to optimize investments. Multiobjective models hold significant promise for developing GI investment portfolios, but need to be developed and tested under real world conditions. We present models for estimating GI costs and for optimizing deployment of GI practices applied to a Piedmont sewershed in Philadelphia's CSO area. © ASCE.
Flynn K.M.,AKRF Inc. |
Linkous B.W.,Cox and Magnani LLC |
Buechter M.T.,Metropolitan St. Louis Sewer District
World Environmental and Water Resources Congress 2012: Crossing Boundaries, Proceedings of the 2012 Congress | Year: 2012
The American Society of Civil and Engineers (ASCE), recently reporting on the environmental, economic, and social impacts associated with aging infrastructure, reinforced the need for proper operation and maintenance practices in order to promote sustainability and resilience of United States infrastructure systems. Essential to the performance of the nation's water resources infrastructure are stormwater best management practices (BMPs). ASCE/EWRI has assembled a Stormwater BMP Maintenance Task Committee to assess and advance the current state of knowledge pertaining to the operation and maintenance of structural BMPs. Structural BMPs encompassed by the scope of the Task Committee include extended detention basins, wet ponds, stormwater wetlands, sand filters, bio-retention practices, vegetated filter strips and wet/dry swales. The BMP Maintenance Task Committee has undertaken a detailed literature review and developed a national survey to assess the effectiveness of current BMP operation and maintenance practices throughout the United States. This paper summarizes the results of the Task Committee literature review and describes the ongoing survey effort. The maintenance survey results are to be evaluated with regard to BMP type, regional influence, and class of asset manager. The survey results and literature review will assist in making recommendations to enhance design methodologies to allow for efficient, regular, and effective maintenance, and to provide contractors and owners with cost effective techniques to manage their stormwater infrastructure. This paper summarizes the progress to date of the Stormwater BMP Maintenance Task Committee's development of detailed operation and maintenance protocols for structural BMPs. © 2012 ASCE.
Seewagen C.L.,University of Western Ontario |
Seewagen C.L.,Wildlife Conservation Society |
Seewagen C.L.,AKRF Inc. |
Guglielmo C.G.,University of Western Ontario |
Morbey Y.E.,University of Western Ontario
Behavioral Ecology | Year: 2013
We used plasma metabolite analysis to assess refueling rates of songbirds at stopover sites in New York and test hypotheses that males refuel faster than females during spring (in 2 species), migrants refuel faster during spring than autumn (in 5 species), and adults refuel faster than juveniles during autumn (in 4 species). Model selection based on Akaike's information criterion indicated that males had higher refueling rates than females during spring in both species tested. Spring migrants had higher refueling rates than autumn migrants in 4 of the 5 species we examined. Juvenile and adult refueling rates during autumn did not differ in any species. Our results indicate that variation in stopover refueling rate can operate as a mechanism for protandry in spring and faster migration during spring than autumn. We found no evidence that juvenile refueling performance during autumn was poorer than that of adults. © 2012 The Author.
Seewagen C.L.,Wildlife Conservation Society |
Seewagen C.L.,University of Western Ontario |
Seewagen C.L.,Pace University |
Seewagen C.L.,AKRF Inc.
Canadian Journal of Zoology | Year: 2013
I examined the relationship between total mercury (THg) and plasma triglyceride (TRIG; an indicator of body mass change) levels in the blood of migrating Northern Waterthrushes (Parkesia noveboracensis (Gmelin, 1789)) to test the hypothesis that mercury has a negative influence on the stopover refueling rates of migratory birds. THg levels averaged 0.42 ppm and ranged 0.09-2.08 ppm. Model selection indicated that THg was not important for explaining variation in TRIG relative to capture time, body mass, and year. Summed model weights also indicated that THg had low relative importance. Capture time appeared alone in the global best model and had the greatest relative importance. Subsets of birds in the 25th and 75th percentiles of THg level did not have different levels of TRIG. THg in most birds was higher than mean blood levels reported for several other long-distance migrants from the same geographic region, but below the lowest blood level recently determined to cause adverse effects (reduced reproductive success) in a passerine (0.7 ppm). Blood THg levels in this study did not seem to affect foraging efficiency or other attributes of Northern Waterthrushes enough to reduce their stopover refueling rate. Research is needed to identify mercury effect levels for neurological, physiological, and behavioral changes that would impair the migration performance of passerine birds.
Flynn K.M.,AKRF Inc. |
Traver R.G.,Villanova University
Ecological Engineering | Year: 2013
This paper presents life cycle assessment (LCA) as a methodology to evaluate environmental, economic, and social performance of green infrastructure stormwater control measures (SCMs). A case study examining a bio-infiltration rain garden at the Villanova University Campus is offered to demonstrate this methodology. The scope of this analysis is cradle to grave benefits and impacts of green infrastructure. Metrics used in this case study to evaluate benefits and impacts include carbon footprint (global warming potential), acidification potential, human health cancer impact, human health non-cancer impact, respiratory effects, eutrophication potential, ozone depletion potential, eco-toxicity, smog formation potential, labor impacts, and life cycle economic costs. Results of this bio-infiltration rain garden case study show that the construction phase is the main contributing life cycle phase for all adverse environmental impacts, as well as total life cycle cost and labor impacts. The majority of these construction phase environmental impacts are attributed to the use of silica sand as a soil amendment for the rain garden media and the use of bark mulch to provide ground cover, repress invasive vegetation, and establish target vegetation. The bio-infiltration rain garden operation phase was found to provide significant avoided environmental impacts relative to the construction phase impacts. These avoided impacts are attributed to urban forest benefits from rain garden vegetation, benefits due to stormwater runoff pollutant treatment by the practice, and benefits to combined sewer systems due to reduced stormwater volume through infiltration and evapo-transpiration. Consideration of multiple rain garden decommissioning phase scenarios makes a case to support the onsite reuse on rain garden media at the end of the practice life. © 2013 Elsevier B.V.
Weinstein M.P.,New Jersey Institute of Technology |
Litvin S.Y.,Stanford University |
Krebs J.M.,AKRF Inc.
Ecological Engineering | Year: 2014
Although the importance of ecosystem services associated with estuarine wetlands and their functional linkages to other estuarine habitats have been increasingly recognized in the past 60 years, the approach to "restoration" and "rehabilitation" of degraded wetland habitats has largely lacked the application of systems thinking and scientific rigor and has resulted in a "disconnect" between the science and practice of wetland restoration. Examples of coastal wetland restoration science are discussed in the context of wetland functions that promote secondary production, ecological fidelity and their "connectedness" to both adjacent waters and the coastal zone. A means to integrate restoration science and practice to inform policy, and the quantification of restored functions in a systems framework is also described in the context of a sample case history. © 2013 Elsevier B.V.
Sachwald B.H.,AKRF Inc.
24th National Conference on Noise Control Engineering 2010, Noise-Con 10, Held Jointly with the 159th Meeting of the Acoustical Society of America | Year: 2010
Urban areas are typically associated with high noise levels. With a population of more than eight million and growing, New York City is one of the largest cities in the world. In New York City, because of the population density and the wide variety of land uses (ex: residential, commercial, transportation, manufacturing and industrial) that exist in close proximity, it is common for a residential building to be located in an area with ambient noise levels that would be considered unsuitable for residential use. To protect inhabitants of a planned building to be located in an area with high ambient noise levels, an (E) designation or a Restrictive Declaration may be used to ensure that the building's interior environment meets a certain acoustical design criterion. In this paper, the (E) designation is defined, its regulatory process is outlined, the acoustical design criterion is discussed, and examples of common mistakes for noise (E) designation projects are listed.
Wu W.,AKRF Inc.
41st International Congress and Exposition on Noise Control Engineering 2012, INTER-NOISE 2012 | Year: 2012
Construction activity generates some of the most disruptive noise in New York City. Noise generated by construction and construction equipment is regulated by the New York City Noise Code. This code requires the adoption and implementation of a noise mitigation plan for each construction site. In response to the Noise Code, AKRF, Inc. has been developing and implementing noise analysis methodology for assessing construction noise impacts since 2007. This paper introduces a useful method for noise assessment within Environmental Impact Statements (EIS) in accordance with the New York City Environmental Quality Review (CEQR) Technical Manual. Various mitigation measures in accordance with the Noise Code regulations are also discussed, and noise analysis results for several large-scale construction projects in New York City are presented. The results indicate that the methodology is effective for assessing construction noise impacts, and the mitigation measures are practical and feasible. The method and mitigation measures discussed may be useful in assessing and minimizing or eliminating noise impacts of projects proposed within metropolitan areas.
Wu W.,AKRF Inc.
Building Acoustics | Year: 2010
Construction noise is one of the most disruptive noise sources in New York City. Large-scale projects especially can take more than a decade to complete, and often be located in areas with various sensitive noise receptors. A technological and reliable approach is required for evaluation of the construction noise and its impact in close proximity. This paper addresses construction noise analysis methods and mitigations, along with a case of noise study (i.e., Fordham University Lincoln Center), in accordance with the CEQR Technical Manual requirements and the New York City Noise Control Code regulations. Analysis methods (i.e., screening, detailed, and refined analyses) for construction noise assessment were introduced, and various construction mitigation options (i.e., source, path, and receiver measures) were examined and developed. The results indicated that the analysis methods were effective to assess noise impacts for large complicated construction projects, the mitigation measures were practical, and noise impacts at adjacent sensitive noise receptors were minimized or eliminated. The relevant experiences learned from the study may be beneficial for use of appropriate analysis methods and practical mitigation measures for large-scale construction projects in high-density urban environments.