Analysis of Rural Interstate Fatality Rates in Consideration of Recent Increases in Maximum Statutory Speed Limits

Author(s):  
Jacob Warner ◽  
Hitesh Chawla ◽  
Chao Zhou ◽  
Peter T. Savolainen

The relationship between traffic safety and speed limits has been an area of significant research. Since the repeal of the National Maximum Speed Law in 1995, states have full autonomy in establishing maximum statutory speed limits. Since 2001, at least 25 states have increased their maximum limits to speeds as high as 85 mph. This study examines changes in rural interstate fatalities from 2001 to 2016 in consideration of such increases. Speed limit policy data include the maximum speed limit for each state–year combination, as well as the proportion of rural interstate mileage posted at each speed limit in each state. Random parameter negative binomial models are estimated to control for unobserved heterogeneity, as well as time-invariant effects unique to each state. The results show that increasing the mileage of rural interstates posted at 70, 75, or 80 mph by 1% is associated with fatality increases of 0.2%, 0.5%, and 0.6%, respectively. These increases are more pronounced than when considering only the maximum statutory limits in each state. The study also examines the influence between these higher limits and the frequency of fatal crashes involving speeding and driver distraction. At the highest limits of 75 and 80 mph, the increases among these subsets of crashes are greater than the increases in total fatalities. Ultimately, this study provides important empirical evidence in support of continuing speed limit policy discussions, in addition to identifying salient analytical concerns that should be considered as a part of longitudinal analyses of state-level fatality data.

2021 ◽  
Vol 11 (12) ◽  
pp. 5710
Author(s):  
Hyungkyu Kim ◽  
Doyoung Jung

The use of an inconsistent speed limit determination method can cause low speed limit compliance. Therefore, we developed an objective methodology based on engineering judgment considering the traffic accident rate in road sections, the degree of roadside development, and the geometric characteristics of road sections in urban roads. The scope of this study is one-way roads with two or more lanes in cities, and appropriate sections were selected among all roads in Seoul. These roads have speed limits of the statutory maximum speed of 80 km/h or lower and are characterized by various speeds according to the function of the road, the roadside development, and traffic conditions. The optimal speed limits of urban roads were estimated by applying the characteristics of variables as adjustment factors based on the statutory maximum speed limit. As a result of investigating and testing various influence variables, the function of roads, the existence of median, the level of curbside parking, the number of roadside access points, and the number of traffic breaks were selected as optional variables that influence the operating speed. The speed limit of one-way roads with two or more lanes in Seoul was approximately 10 km/h lower than the current speed limit. The existing speed limits of the roads were applied uniformly considering only the functional road class. However, considering the road environment, the speed limit should be applied differently for each road. In the future, if the collection scope and real-time collection of road environment information can be determined, the GIS visualization of traffic safety information will be possible for all road sections and the safety of road users can be ensured.


Author(s):  
Do Duy Dinh ◽  
Thai Hong Nam ◽  
Vu Hoai Nam

This study is to assess the effects of raising speed limits to vehicle operating speeds on rural divided highways in Vietnam. Vehicle speeds were recorded at three different sites of three routes during the daytime and nighttime, both before and after speed limits on these sites increasing from 80 km/h to 90 km/h. The results have shown that the percentage of speeds exceeding speed limits had a wide range from 0% to nearly 30% with regard to different locations, survey time and speed limits. The extent of speeding in some cases was very high even after speed limit increased. It was found that in most cases, the changes in mean speeds after a higher speed limit was applied were statistically significant at the p-value of 0.05, however, the magnitudes of the mean change varied considerably between locations and survey times. Because four out of six cases under the study having mean speeds increased by over 10 km/h after setting up a higher speed limit, this study suggests that further appropriate measures of speed control and speed management should be applied along with increasing speed limit to ensure traffic safety on rural divided highways in Vietnam. Article history: Received 27 March 2018, Revised 18 April 2018, Accepted 27 April 2018


1997 ◽  
Vol 1587 (1) ◽  
pp. 113-120
Author(s):  
Maureen A. Mullen ◽  
James H. Wilson ◽  
Laura Gottsman ◽  
Robert B. Noland ◽  
William L. Schroeer

The National Highway System (NHS) bill passed by Congress in November 1995 eliminated the national maximum speed limit. It has allowed states to set their own speed limits, which many have changed during the past year. This analysis examines the impact of speed limit changes 1 year after passage of the NHS. Oxides of nitrogen (NOx), carbon monoxide, and volatile organic compounds are analyzed and are found to have increased nationwide by up to 6, 7, and 2 percent, respectively. Much of the increase has occurred in western states, which generally have increased vehicle speeds more than in eastern and midwestern states. For example, in Texas NOx emissions are estimated to have increased by 35 percent due to large increases in highway and arterial speed limits.


2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Minho Park ◽  
Dongmin Lee

This study explored factors affecting traffic accidents in roadway segments with and without lighting systems using a random parameter negative binomial model. This study sought to make up for a shortcoming of the fixed parameter model that constrained the estimated parameters to be fixed across observations, by applying random parameters that can take into account unobserved heterogeneity. Three variables had a random parameter among nine significant variables in segments with lighting systems, while seven of the eleven significant variables in a segment without a lighting system had random parameters. The different influence of interstate highway geometrics on vehicle crashes with and without lighting systems found through this study considering unobserved heterogeneity may hopefully help reduce accident frequencies and consider installation of lighting systems on interstate highways in the future.


2017 ◽  
Vol 28 (04) ◽  
pp. 321-333 ◽  
Author(s):  
Benjamin Russell ◽  
Susan Stepney

We study the maximum speed of quantum computation and how it is affected by limitations on physical resources. We show how the resulting concepts generalize to a broader class of physical models of computation within dynamical systems and introduce a specific algebraic structure representing these speed limits. We derive a family of quantum speed limit results in resource-constrained quantum systems with pure states and a finite dimensional state space, by using a geometric method based on right invariant action functionals on [Formula: see text]. We show that when the action functional is bi-invariant, the minimum time for implementing any quantum gate using a potentially time-dependent Hamiltonian is equal to the minimum time when using a constant Hamiltonian, thus constant Hamiltonians are time optimal for these constraints. We give an explicit formula for the time in these cases, in terms of the resource constraint. We show how our method produces a rich family of speed limit results, of which the generalized Margolus–Levitin theorem and the Mandelstam–Tamm inequality are special cases. We discuss the broader context of geometric approaches to speed limits in physical computation, including the way geometric approaches to quantum speed limits are a model for physical speed limits to computation arising from a limited resource.


Author(s):  
Young-Jun Kweon ◽  
Kara M. Kockelman

A better understanding of attitudes and behavioral principles underlying driving behavior and traffic safety issues can contribute to design and policy solutions, such as speed limits and seat belt legislation. This work examines the Motor Vehicle Occupant Safety Surveys (MVOSS) dataset to illuminate drivers' seatbelt use, driving speed choices, drinking-and-driving tendencies, along with their attitudes towards speed limits and seat belt laws. Ordered probit, negative binomial, and linear regression models were used for the data analysis, and several interesting results emerged. The number and variety of results feasible with this single dataset are instructive as well as intriguing.


2018 ◽  
Vol 11 (1) ◽  
pp. 119 ◽  
Author(s):  
Reza Shirazinejad ◽  
Sunanda Dissanayake ◽  
Ahmed Al-Bayati ◽  
David York

In the summer of 2011, a change in the Kansas laws came into effect, increasing the speed limit on a selected set of freeway sections from 70 mph to 75 mph. Higher speeds were thought to have economic benefits, mostly because the travel time reduction means people reach their destinations more quickly. In this study, the sections where the speed limits remained unchanged, are compared to freeway sections that have been influenced by speed limit increase, to evaluate safety effectiveness. The study utilizes the before-and-after study with comparison group method to assess the safety effects provided in the Highway Safety Manual (HSM). Two crash datasets, obtained by considering three years before and three years after the speed limit increase, were compared in order to evaluate the safety effects of the speed limit change. The crash modification factors (CMFs) were estimated, which showed that there was a 27% increase in total crashes and a 35% increase in fatal and injury crashes across all sections after the speed limit change, and these increases were statistically significant at 95% confidence level. These confounding results show that the speed limit increase has not been beneficial for traffic safety in Kansas, and hence it is important to be cautious in such future situations. Also, additional data have been presented which would be beneficial in identifying and understanding any behavior change in drivers following a speed limit increase.


2018 ◽  
Vol 80 (5) ◽  
Author(s):  
Gito Sugiyanto ◽  
Siti Malkhamah

Speed is one of the main risk factors in road traffic safety and become a traffic problem in developing countries. Three factors that cause accidents are human factor, vehicle, and environment. Speeding is one of the main cause factors in traffic accident. Traffic speed must be limited adjust with the activities in the street and potential accident. The aim of this research is to determine the maximum speed limit in urban road to increase traffic safety and to analyze the percentage of vehicle exceeding speed limit. The method to determine maximum speed limits using 85th percentile. Based on the analysis result, the proposed maximum speed limit on urban road for arterial road type 4/2-UD residential and 4/2-UD CBD is 60 km/h for motorcycle and passenger car, 55 km/h for pick up and light truck, and 50 km/h for bus and truck. Proposed maximum speed limit for collector road type 2/1-UD office area is 45 km/h for motorcycle and 40 km/h for four-wheeled vehicles or more while for collector road type 2/1-UD CBD is 40 km/h for motorcycle and 35 km/h for four-wheeled vehicles or more. The installation of speed limit sign is less effective to reduce the vehicle speed, the speed only reduce 2.9-55 km/h (5.6-10.1%). More than 46.5% of motorcycle users ride exceeding speed limit followed by the passenger cars users (39.43%), microbus/city bus at 31.63%, bus Trans at 28.75%, pick up and light truck at 24.69%. The maximum speed limit in school safety zone on hours/after school is 30 km/h with the consideration that the pedestrian fatality rate on 30 km/h has probability of death 10%.


2013 ◽  
Vol 723 ◽  
pp. 189-195
Author(s):  
Yong Fang ◽  
Zhong Yin Guo

To solve the problems in the current deterministic method of a maximum speed limit for expressway, a method of dynamic speed limit on expressway under complex climate was presented which was based on pavement skid-resistant performance. Firstly, the variation of pavement skid-resistant performance under complex climate conditions was analysed based on research results and certain experimental statistic data. By analysing the influence rule of AC-16 and SMA-16 pavement texture, pavement temperature, water film thickness, ice thickness, vehicle speed to pavement Skid-Resistant Performance, pavement actual friction coefficient calculation model and reference standard were established under different pavement condition Then, by analysing the geometry line indexes, pavement conditions and vehicle dynamics, the critical sideslip speed and critical longitudinal-driving safety speed was formulated; therefore, with critical speed as a constraint of safety driving and interval classification of complex climatic conditions, the dynamic speed calculate method and safety speed control standard were proposed under various pavements conditions, visibilities and traffic environments. This method for overcoming the weakness of a maximum speed limit of expressway operation and improving traffic safety is helpful.


2020 ◽  
Vol 2 (3) ◽  
pp. 149
Author(s):  
Willy Kriswardhana ◽  
Sonya Sulistyono ◽  
Iin Ervina ◽  
Dadang Supriyanto ◽  
Nunung Nuring Hayati ◽  
...  

Driving at high speed has negative consequences, namely, the high number of accidents. Several factors have been considered as causes of the increasing severity of victims of traffic accidents, such as a human, vehicle, and environmental factors. The risky driving behavior factor is a factor that needs to be considered in traffic safety studies. This study aims to determine the probability model of speeding behavior based on several driver characteristics and their relationship to accident involvement. This study used a binary logistic regression method to determine the probability of driving behavior exceeding the speed limit and accident involvement. The results showed that the younger a person is, the higher the probability of breaking the maximum speed limit. Furthermore, driving experience also shows a similar trend, where the longer the driving experience of someone, the less likely it is to be involved in an accident. Directions for further research are also presented. Berkendara dengan kecepatan tinggi mempunyai konsekuensi negatif, yaitu tingginya angka kecelakaan. Beberapa faktor telah dipertimbangkan sebagai penyebab dari peningkatan tingkat keparahan korban kecelakaan lalulintas. Faktor tersebut seperti faktor manusia, kendaraan, dan lingkungan. Faktor perilaku berkendara yang berbahaya, menjadi faktor yang perlu diperhatikan dalam kajian keselamatan lalulintas. Penelitian ini bertujuan untuk mengetahui model probabilitas pada perilaku speeding berdasarkan beberapa karakteristik pengendara, serta hubungannya dengan keterlibatan kecelakaan. Penelitian ini menggunakan metode regresi logistik biner untuk mengetahui probabilitas perilaku berkendara melebihi batas kecepatan dan keterlibatan kecelakaan. Hasil penelitian menunjukkan bahwa semakin muda usia seseorang, maka semakin tinggi probabilitasnya dalam melanggar batas kecepatan maksimum. Lebih lanjut diperlihatkan bahwa pengalaman mengemudi juga menunjukkan tren yang serupa. Pengalaman mengemudi seseroang, yang lebih lama akan memperkecil kemungkinan dalam keterlibatan kecelakaan. Arahan untuk penelitian selanjutnya juga ditampilkan.


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