Safety Evaluation of Pedestrian Countdown Signals: Definitive Results from Two Cities in the United States

Author(s):  
Raghavan Srinivasan ◽  
Bo Lan ◽  
Daniel Carter ◽  
Sarah Smith ◽  
Bhagwant Persaud ◽  
...  

The pedestrian countdown signals (PCS) treatment involves the display of a numerical countdown that shows how many seconds are left in the flashing DON’T WALK interval. Although many studies have attempted to evaluate the safety of PCS, the results have been inconsistent for many reasons, including inadequate sample size and the inability to control for possible bias from regression to the mean and from exposure. This study performed a before-after empirical Bayes analysis using data from 115 treated intersections in Charlotte, North Carolina and 218 treated intersections in Philadelphia, Pennsylvania to evaluate the safety effects of PCS. The evaluation also included 136 reference intersections in Charlotte, and 597 reference intersections in Philadelphia. Following the implementation of PCS, total crashes decreased by approximately 8% and rear-end crashes decreased by approximately 12%, and these reductions were statistically significant at the 95% confidence level. Pedestrian crashes decreased by about 9% and this reduction was statistically significant at the 90% confidence level. Economic analysis revealed a benefit-cost ratio of 23 with a low of 13 and a high of 32.

Author(s):  
Thanh Q. Le ◽  
Frank Gross ◽  
Timothy Harmon

Packages of intersection treatments—including signing, pavement marking, and signal enhancements—were installed at many signalized and stop-controlled intersections in South Carolina. This study evaluated the overall safety-effectiveness of the concurrent implementation of these systemic low-cost treatments as part of the FHWA Evaluations of Low Cost Safety Improvements Pooled Fund. The data set included both urban and rural three-leg and four-leg intersections with two or four lanes on the major road. The study employed an empirical Bayes before-and-after analysis. The aggregate results indicate reductions for all crash types analyzed in this study. For signalized intersections, the crash modification factors (CMFs) are 0.955, 0.893, 0.974, 0.883, and 0.969 for total, fatal and injury, rear-end, right-angle, and nighttime crashes, respectively. The CMFs for fatal and injury and right-angle crashes are statistically significant at the 95% confidence level and the CMF for total crashes is statistically significant at the 90% confidence level. For stop-controlled intersections, the CMFs are 0.917, 0.899, 0.933, 0.941, and 0.853 for total, fatal and injury, rear-end, right-angle, and nighttime crashes, respectively. All CMFs for stop-controlled intersections are statistically significant at the 95% confidence level. An economic analysis shows that systemic, low-cost intersection treatments are cost-effective with conservative benefit–cost ratio estimates of 4.1 for total crashes at signalized intersections and 12.4 for total crashes at stop-controlled intersections.


Author(s):  
Timothy S. Nye ◽  
Christopher M. Cunningham ◽  
Elizabeth Byrom

A national-level safety evaluation of Diverging Diamond Interchanges (DDIs) in the United States was completed. This study aimed to update previous evaluations and to expand the treatment group size of previous studies to provide a more robust and reliable safety assessment of DDI deployments. For this particular treatment, it was determined that, of the observational before-and-after evaluation methodologies, the comparison group approach yields the best evaluation results. The naïve method can be influenced by outside factors that cannot be accounted for (weather, crash reporting tendencies, etc.). The empirical Bayes method is unnecessary as DDIs are installed for operational benefits, meaning that risk of selection bias and regression-to-the-mean is minimal. This study recommends a total crashes crash modification factor (CMF) of 0.633 based on the comparison group analysis of 26 DDIs in 11 states. The comparison group method was also applied to a variety of crash variables for this study. Angle, rear-end, and sideswipe crashes were found to have CMFs of 0.441, 0.549, and 1.139, respectively. Fatal-and-injury crashes provided a CMF of 0.461. Daytime and nighttime crashes provided CMFs of 0.648 and 0.638, respectively.


2016 ◽  
Vol 131 (4) ◽  
pp. 1795-1848 ◽  
Author(s):  
Patrick Kline ◽  
Christopher R. Walters

Abstract We use data from the Head Start Impact Study (HSIS) to evaluate the cost-effectiveness of Head Start, the largest early childhood education program in the United States. Head Start draws roughly a third of its participants from competing preschool programs, many of which receive public funds. We show that accounting for the fiscal impacts of such program substitution pushes estimates of Head Start’s benefit-cost ratio well above one under a wide range of assumptions on the structure of the market for preschool services and the dollar value of test score gains. To parse the program’s test score impacts relative to home care and competing preschools, we selection-correct test scores in each care environment using excluded interactions between experimental assignments and household characteristics. We find that Head Start generates larger test score gains for children who would not otherwise attend preschool and for children who are less likely to participate in the program.


2018 ◽  
Vol 33 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Debalin Sarangi ◽  
Amit J. Jhala

AbstractDue to depressed corn and soybean prices over the last few years in the United States, growers in Nebraska are showing interest in no-tillage (hereafter referred to as no-till) conventional (non–genetically engineered [non-GE]) soybean production. Due to the increasing number of herbicide-resistant weeds in the United States, weed control in no-till non-GE soybean using POST herbicides is a challenge. The objectives of this study were to compare PRE-only, PRE followed by (fb) POST, and PRE fb POST with residual (POST-WR) herbicide programs for Palmer amaranth and velvetleaf control and soybean injury and yield, as well as to estimate the gross profit margins and benefit–cost ratio of herbicide programs. A field experiment was conducted in 2016 and 2017 at Clay Center, NE. The PRE herbicides tested in this study resulted in ≥95% Palmer amaranth and velvetleaf control at 28 d after PRE (DAPRE). Averaged across the programs, the PRE-only program controlled Palmer amaranth 66%, whereas 86% and 97% control was obtained with the PRE fb POST and PRE fb POST-WR programs, respectively, at 28 d after POST (DAPOST). At 28 DAPOST, the PRE fb POST herbicide programs controlled velvetleaf 94%, whereas the PRE-only program resulted in 85% control. Mixing soil-residual herbicides with foliar-active POST programs did not improve velvetleaf control. Averaged across herbicide programs, PRE fb POST programs increased soybean yield by 10% and 41% in 2016 and 2017, respectively, over the PRE-only programs. Moreover, PRE fb POST-WR programs produced 7% and 40% higher soybean yield in 2016 and 2017, respectively, compared with the PRE fb POST programs. The gross profit margin (US$1,184.3 ha−1) was highest under flumioxazin/pyroxasulfone (PRE) fb fluthiacet-methyl plusS-metolachlor/fomesafen (POST-WR) treatment; however, the benefit–cost ratio was highest (6.1) with the PRE-only program of flumioxazin/chlorimuron-ethyl.


Author(s):  
Patricia Pinamang Acheampong ◽  
Marian Dorcas Quain ◽  
David Appiah-Kubi ◽  
Jonas Osei-Adu ◽  
Stella Ama Ennin ◽  
...  

The supply of seed yams for intensive yam production is hindered by many constraints, including diseases and pest infestations as well as the unavailability of quality planting material. The combination of tissue culture and aeroponics system is perceived to be the way towards clean and adequate supply of seed yam for enhanced yam production. However, the system is considered as expensive for any individual to implement. In order to encourage private sector to participate in this venture, the economic analysis determining the feasibility and viability of using aeroponics in seed yam production was performed. Using data from established tissue culture and aeroponics system in Ghana, the fixed cost and variable cost parameters as well as production costs were obtained. Results revealed that total cost of building aeroponics structure amounted to GH₵ 94,178.00 (USD 17,938.70). Annual cost of aeroponics structure was GH₵ 9,417.82 (USD 1,793.87). Annual total cost of production totalled GH₵ 204,391.75 (USD 38,931.61). Annual net revenue was GH₵ 75,888.00 (USD 14,454.86). Payback period was 15 months and benefit cost ratio was 1.4. Aeroponics system for seed yam production is therefore profitable since short period would be needed to recoup investment. For food security and creation of workplaces, government could partner with the private sector in the establishment of aeroponics systems to increase yam production and export.


2006 ◽  
Vol 11 (1) ◽  
pp. 77-94 ◽  
Author(s):  
ADAM G. DRUCKER

This paper adapts the safe minimum standard (SMS) approach so as to explore its use as a potential policy decision support tool that can be applied to issues related to the conservation and sustainable use of farm animal genetic resource (AnGR) diversity. Empirical SMS cost estimates are obtained using data from three AnGR economics case studies in Mexico and Italy. The findings support our hypothesis that the costs of implementing an SMS are low, both when compared with the size of subsidies currently being provided to the livestock sector (<1 percent of the total subsidy) and with regard to the benefits of conservation (benefit-cost ratio of >2.9).Nevertheless, despite providing a potentially useful AnGR conservation decision support tool, a critical assessment of the application reveals that a much more extensive quantification of the components required to determine SMS costs needs to be undertaken before this tool can be applied in practice.


2021 ◽  
Author(s):  
Rui Li ◽  
Hanting Liu ◽  
Christopher Kit Fairley ◽  
Zhuoru Zou ◽  
Li Xie ◽  
...  

Background: Over 86% of older adults aged ≥65 years are fully vaccinated against SARS-COV-2 in the United States (US). Waning protection of the existing vaccines promotes the new vaccination strategies, such as providing a booster shot for those fully vaccinated. Methods: We developed a decision-analytic Markov model of COVID-19 to evaluate the cost-effectiveness of a booster strategy of Pfizer-BioNTech BNT162b2 (administered 6 months after 2nd dose) in those aged ≥65 years, from a healthcare system perspective. Findings: Compared with 2-doses of BNT162b2 without a booster, the booster strategy in a 100,000 cohort of older adults would incur an additional cost of $3.4 million, but save $6.7 million in direct medical costs in 180 days. This corresponds to a benefit-cost ratio of 1.95 and a net monetary benefit of $3.4 million. Probabilistic sensitivity analysis indicates that with a COVID-19 incidence of 9.1/100,000 person-day, a booster strategy has a high chance (67%) of being cost-effective. The cost-effectiveness of the booster strategy is highly sensitive to the population incidence of COVID-19, with a cost-effectiveness threshold of 8.1/100,000 person-day. This threshold will increase with a decrease in vaccine and booster efficacies. Doubling the vaccination cost or halving the medical cost for COVID-19 treatment alone would not alter the conclusion of cost-effectiveness, but certain combinations of the two might render the booster strategy not cost-effective. Interpretation: Offering BNT162b2 boosters to older adults aged ≥65 years in the US is likely to be cost-effective. Less efficacious vaccines and boosters may still be cost-effective in settings of high SARS-COV-2 transmission. Funding: National Natural Science Foundation of China. Berlina and Bill Gates Foundation


Author(s):  
Cary Jim ◽  
Sarah Evans ◽  
Alison Grant

In this paper, we share the initial findings from a multi-disciplinary project by Team D2IE (Digital Divide and Inclusion in Education), the recent first-place winner of the Global XPRIZE Education Open Data Challenge, where they investigated how digital infrastructure and internet connectivity varies among K-12 students at the county level across the United States. Two quantitative measures (Student Digital Opportunity and Benefit-Cost Ratio) and three interactive maps were developed from socio-technical and economic perspectives to support decision-making. The three interactive maps allow stakeholders to evaluate digital access, usage, cost, and economic benefits at the county level across the country.


2022 ◽  
Vol 14 (2) ◽  
pp. 649
Author(s):  
Anne Wambui Mumbi ◽  
Tsunemi Watanabe

This study analyzed the cost implications of using suitable technologies and the cost of inaction when addressing water pollution. This was achieved by developing three main models for the costs (model one) and benefits (model two and model three). The first model accounts for the operational costs of adopting suitable technologies, namely the use of diatomaceous earth for textile wastewater treatment. The second model analyzed the cost of inaction through analyzing the cost of treatment for water pollution-related diseases for the affected population. The occurrence and cost of treatment for three diseases, namely diarrhea, amoebiasis and bacterial infection, were used as indicators of water pollution in the area. The third model included the contingent valuation method (CVM) data on the willingness to pay for environmental restoration of the surveyed population. The benefit–cost ratio (BCR) of the resulting data from the three models were used to highlight the economic viability of the proposed project. A BCR of (0.67) for the cost of the proposed project versus the benefits of the project on human health using data from one hospital was obtained. There is a high possibility that the real BCR would increase if more data from other hospitals or other diseases were included. The results imply that the use of D.E can be considered a good candidate for treating wastewater. To thoroughly discuss the BCR of treating wastewater from one factory, the BCR of the proposed restoration project along River Sosiani, and the value of using DE as suitable technology, more studies are needed to evaluate the unaccounted costs and benefits for accurate economic estimations of the proposed project. The outcome of the study is a framework of numbers and figures that can be presented to decision makers and policy makers as critical information when making decisions.


Author(s):  
Jaeyoung Lee ◽  
Mohamed Abdel-Aty ◽  
Jung-Han Wang ◽  
Chanyoung Lee

A motorcyclist helmet is considered important safety equipment because it prevents or minimizes head and brain injuries, which are often fatal. Hence, in the 1960s and 1970s, most of the states in the United States enacted the universal helmet law (UHL) requiring all motorcyclists to wear helmets. Many researchers have examined the effect of the helmet law changes by using before-and-after studies and found that repealing the law had a negative effect on motorcyclists. In this study, the authors have attempted to explore the long-term impacts of repeal and reinstatement of the UHL by using 13 to 16 years of data. A before-and-after study with a comparison group and empirical Bayes methods was adopted to account for the passage of time and its effect on other factors such as exposure, maturation, trend, and regression-to-the-mean bias. A range of safety performance functions was developed on the basis of counties and parishes, and the expected fatal motorcycle crashes were calculated. The results showed that the UHL repeal still had significant effects on motorcycle fatal crash counts even 7 to 12 years after the repeal of the law. The crash modification factors showed that the UHL repeal increased the number of motorcycle fatal crashes by 15% to 41%, whereas reinstatement of the UHL decreased it by 21% to 27%. It is expected that the results from this study could be helpful for state policy makers to clearly understand the effects of the UHL on reducing motorcycle fatal crashes.


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