Coupling Impacts of Spray and Rainfall on Road Visibility and Vehicle Speeds: A Simulation-based Analysis

Author(s):  
Shuyi Wang ◽  
Tianheng Chen ◽  
Bin Yu ◽  
Yue Sun ◽  
Xiaochun Qin

Impaired visibility resulting from rainfall contributes greatly to the occurrence of traffic accidents. This study presents a numerical simulation approach to analyze the extent to which the coupling of spray and raindrops reduces visibility and thus proposes safe speeds against inadequate visibility. The spray-raindrop coupling particles were modeled by considering the real highway design parameters and rainfall conditions. The road visibility was estimated through simulating the multiple scattering process of taillights in the spray-rain medium, and the maximum safe speed against inadequate visibility was then derived by comparing the visibility with the required stopping sight distance. Results show that: 1) either a high speed of the front truck or a thick water-film results in a significant reduction in road visibility and the maximum safe speed of the ego vehicle, 2) front vehicle speed plays a more important role in visibility reduction than the water-film thickness does.

1992 ◽  
Vol 19 (5) ◽  
pp. 760-766 ◽  
Author(s):  
Francis P. D. Navin

Highway engineers, when asked to state the safety of a particular design, are usually at a loss to give a single meaningful measure as is possible in structural or geotechnical engineering. This paper outlines a method to estimate the margin of safety and reliability index for isolated highway components. The stopping sight distance is used to demonstrate the method. The method uses the basic highway design equations. On the assumption that the variables are random, the expected value of the mean and the variance are estimated; and from these the margin of safety and the reliability index are calculated. The most likely combination of variables for the existing design condition may also be estimated. The variables included represent the characteristics of the driver, the vehicle, and the road surface.A method is proposed to specify the design parameter's value representing a road's strategic importance, the users, the vehicles, the drivers, the environment, the terrain, and the standard of design and construction. The apparent advantage of the proposed reliability-based method is that the designer must explicitly specify the importance of the modifying factors and may also more closely investigate the behaviour of the variables in the design parameters in the critical region near noncompliance. Key words: limit states design, stopping sight distance, safety, highway design, reliability.


Author(s):  
Mohamed Sarhan ◽  
Yasser Hassan

The potential usefulness of reliability analysis has recently been stressed in many engineering applications. Given the variability in the design parameters, a reliability-based probabilistic approach is well suited to replace the current deterministic highway design practice. However, progress in this regard is generally slow. In this study, the reliability analysis was used to estimate the probability of hazard (POH) that might result from insufficiency of sight distances. As an application, the available sight distance was checked against required stopping sight distance on an assumed road segment. Variation of the design parameters was addressed with Monte Carlo simulation using 100,000 sets of design parameters based on distributions available in the literature. A computer program was developed to use these sets of design parameters to calculate the profiles of available and required stopping sight distances in two- and three-dimensional projections as well as the profile of POH. The approach was applied to a horizontal curve overlapping with flat grade, crest curves, and sag curves in a cut section where the side slope would restrict the sightline. The analysis showed that the current deterministic approach yields very conservative estimates of available and required stopping sight distance, resulting in very low POH. The application example also showed the change of POH with the change of vertical alignment parameters.


BANGUNAN ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 20
Author(s):  
Nando Ramadhani Nur Adnan ◽  
Pranoto Pranoto ◽  
Boedi Rahardjo

Abstrak:Kondisi geometrik jalan yang tidak sesuai dengan standar teknis perencanaan dapat menyebabkan terjadinya kecelakaan lalu lintas. Tikungan SDN 3 Selorejo Kabupaten Blitar merupakan salah satu tikungan yang tidak memenuhi syarat perencanaan geometrik jalan di Indonesia. Penelitian ini menggunakan metode analisis deskriptif kuantitatif. Pengumpulan data dilakukan dengan metode survei lokasi selama 4 hari. Data primer meliputi data volume lalu lintas, kecepatan kendaraan, perlengkapan jalan, pelebaran jalan, dan geometrik jalan. Data sekunder data kecelakaan lalu lintas dan geometrik existing. Hasil penelitian mendapatkan: (1) karakteristik lalu lintas memiliki volume maksimum terjadi pada hari Senin sebesar 17221 smp/hari yang di dominasi oleh kendaraan ringan (LV) sebesar 46,13 persen, kecepatan kendaraan rata-rata sebesar 47,95 km/jam dengan kecepatan tertinggi di dominasi oleh kendaraan bermotor (MC) yang memiliki rata-rata kecepatan sebesar 62,73 km/jam dengan kecepatan tertinggi yang pernah tercatat dalam pengamatan sebesar 87,64 km/jam, dan kepadatan kendaraan tertinggi terjadi pada hari Senin sebesar 32,73 smp/km, (2) kondisi geometrik jalan pada beberapa aspek perencanaan seperti nilai superelevasi existing memiliki nilai sebesar 11,50 persen, sedangkan pada hasil perencanaan diperoleh superelevasi sebesar 9,89 persen, lengkung peralihan existing memiliki panjang 40 meter, sedangkan pada hasil perencanaan diperoleh nilai lengkung peralihan sepanjang 54,56 meter, dan pelebaran jalan existing memiliki lebar jalan sebesar 0,3 meter, sedangkan pada hasil perencanaan diperoleh lebar jalan sebesar 0,7124 meter, (3) faktor-faktor penyebab kecelakaan di dominasi oleh faktor manusia sebesar 57,14 persen dengan sebab kejadian yang sering dialami adalah kecepatan tinggi dan mengantuk, faktor kendaraan sebesar 21,43 persen dengan sebab kejadian yang dialami karena rem blong, muatan berlebih, dan ban pecah, sedangkan pada faktor jalan sebesar 21,43 persen yang selalu disebabkan oleh kemiringan jalan pada tikungan.Kata-kata kunci: Geometrik Jalan, Tikungan, Faktor Kecelakaan, Lalu LintasAbstract: Geometric conditions that are not in accordance with the technical planning standards can cause traffic accidents. SDN 3 Selorejo Bend Blitar Regency is one of the bends that do not meet the geometric planning requirements for roads in Indonesia. This research uses quantitative descriptive analysis method. Data collection was carried out using the location survey method for 4 days. Primary data include data on traffic volume, vehicle speed, road equipment, road widening and road geometry. Secondary data on existing traffic and geometric accident data. The results get: (1) traffic characteristics have a maximum volume occurs on Monday at 17221 pcu / day which is dominated by light vehicles (LV) of 46.13%, the average vehicle speed of 47.95 km / hour with the highest speed is dominated by motorized vehicles (MC) which have an average speed of 62.73 km / hour with the highest speed ever recorded in the observation of 87.64 km / hour, and the highest vehicle density occurs on Monday at 32, 73 smp / km, (2) the geometric condition of the road in some aspects of planning such as the existing superelevation value has a value of 11.50 percent, while the results of the planning obtained superelevation of 9.89 percent, the existing transition curve has a length of 40 meters, while the results planning obtained the value of the transition curve along 54.56 meters, and the widening of the existing road has a road width of 0.3 meters, while the results obtained from the planning of the road of 0.7124 meters, (3) factors that cause accidents are dominated by human factors of 57.14 percent because the events that are often experienced are high speed and sleepy, vehicle factors of 21.43 percent with the causes of events experienced due to brakes blown, overloaded, and broken tires, while the road factor of 21.43 percent which is always caused by the slope of the road at the bend.Keywords: Geometric Road, Bend, Accident Factor, Traffic


2021 ◽  
Vol 21 (2) ◽  
pp. 101-108
Author(s):  
Arivia Shehera Kurniastuti ◽  
Novita Sari ◽  
Sulistyo Sutanto

Abstract   The number of traffic accidents that occur in Indramayu Regency continues to increase and causes many casualties and material losses. From the available data, it is known that there is one road section which is an accident-prone area, namely the North Coast Java Road section, KM 46-47, which is located in Patrol District, Indramayu Regency. The flow and speed of traffic on this road is quite high, because of its function as a primary arterial road. This study aims to improve safety on the North Coast Java Road section, KM 46-47. The method used is in the form of observation and field data collection. Furthermore, the data obtained is processed, analyzed, and followed by formulating appropriate recommendations. This study shows that the main cause of accidents is the human factor, especially those related to high traffic speeds. To improve the existing conditions, it is proposed to provide road equipment, especially traffic signs, which are adjusted to the stopping sight distance required by motorized vehicles using the road. In addition, it is necessary to apply speed management as part of efforts to improve traffic safety.   Keywords: traffic accident; stopping sight distance; road equipment, traffic speed; traffic signs.     Abstrak   Angka kecelakaan lalu lintas yang terjadi di Kabupaten Indramayu terus meningkat dan menyebabkan banyak korban jiwa dan kerugian material. Dari data yang ada diketahui bahwa terdapat satu ruas jalan yang termasuk daerah rawan kecelakaan, yaitu ruas Jalan Pantai Utara Jawa, KM 46-47, yang terletak di Kecamatan Patrol, Kabupaten Indramayu. Arus dan kecepatan lalu lintas di ruas jalan tersebut cukup tinggi, karena fungsinya sebagai jalan arteri primer. Studi ini bertujuan untuk meningkatkan keselamatan di ruas Jalan Pantai Utara Jawa KM 46-47. Metode yang digunakan berupa observasi dan pengumpulan data lapangan. Selanjutnya data yang diperoleh diolah, dianalisis, kemudian dirumuskan rekomendasi yang tepat. Studi ini menunjukkan bahwa faktor penyebab kecelakaan yang utama adalah faktor manusia, khususnya yang berhubungan dengan kecepatan lalu lintas yang tinggi. Untuk memperbaiki kondisi yang ada, diusulkan pemberian perlengkapan jalan, khususnya rambu lalu lintas, yang disesuaikan dengan jarak pandang henti yang diperlukan oleh kendaraan bermotor yang melintasi jalan tersebut. Selain itu perlu diterapkan manajemen kecepatan sebagai bagian upaya meningkatkan keselamatan lalu lintas.   Kata-kata kunci: kecelakaan lalu lintas; jarak pandang henti; perlengkapan jalan, kecepatan lalu lintas; rambu lalu lintas.


Vehicles ◽  
2022 ◽  
Vol 4 (1) ◽  
pp. 30-41
Author(s):  
Bruce W. Jo

High-speed capsular vehicles are firstly suggested as an idea by Elon Musk of Tesla Company. Unlike conventional high-speed trains, capsular vehicles are individual vessels carrying passengers and freight with the expected maximum speed of near 1200 [km/h] in a near-vacuum tunnel. More individual vehicle speed, dispatch, and position control in the operational aspect are expected over connected trains. This numerical study and investigation evaluate and analyze inter-distance control and their characteristics for high-speed capsular vehicles and their operational aspects. Among many aspects of operation, the inter-distance of multiple vehicles is critical toward passenger/freight flow rate and infrastructural investment. In this paper, the system’s equation, equation of the motion, and various characteristics of the system are introduced, and in particular control design parameters for inter-distance control and actuation are numerically shown. As a conclusion, (1) Inter-distance between vehicles is a function of error rate and second car start time, the magnitude range is determined by second car start time, (2) Inter-distance fluctuation rate is a function of error rate and second car start time, however; it can be minimized by choosing the correct second car start time, and (3) If the second car start time is chosen an integer number of push-down cycle time at specific velocity error rate, the inter-distance fluctuation can be zero.


Recently, accidents involving ground transportations are getting worse and more serious. Indonesian State Police (Korlantas POLRI) recorded the number of accidents in 2018 as many as 109,215 accidents. The number has incresed 4.69 percent compared to 2017 as many as 104,327 events. Road traffic accidents are caused by human error, the driver in this case. The driver's mistake is influenced by several factors, one of them is they cannot expect the road condition when they drive a vehicle at high speed. To solve this problem, drivers need information that can show road conditions. So, we present a new approach for detecting damaged roads by applying augmented reality technology. This research produces a road condition information system to help drivers get information about road conditions via smartphone. This system uses augmented reality technology with a markerless GPS Based Tracking method. The development of this system requires several stages such as collecting the data, data conversion, data classification, and views road condition. The researchers gathered the road condition data from the Public Work Department Semarang. This department itself undertakes a task to control the road condition in Semarang The trial of this system includes all drivers in Semarang city. Based on the results of the questionnaire responded to by 93 respondents, this test obtained an average value of 68%. So this system gets a pretty good response from the driver. Through this system, all drivers can avoid the damaged road condition which can cause traffic-congested and accident.


2011 ◽  
Vol 138-139 ◽  
pp. 146-152
Author(s):  
Guo He Guo ◽  
Yu Feng Bai ◽  
Tao Wang

Based on the significant destructive effect of heavy vehicle on uneven roads, two simplified models of pavement unevenness and vehicle dynamic load were established in accordance with D'A lembert principle, and Matlab software was used to analyze the changing law of dynamic load under the conditions of different road unevenness, vehicle speed and load. The results show that vehicles running on uneven road may produce more cumulative damages than static load, and DLC (dynamic load coefficient) changes in wide range, maximum up to 2.0 or more; the effect of speed and load on dynamic load is complex, and due to multi-factor interaction, DLC doesn’t consistently increase or decrease with speed and load increasing. Although the dynamic load level caused by high-speed heavy vehicle is not necessarily too high, its impact on the road can not be ignored.


Author(s):  
Daniel B. Fambro ◽  
Rodger J. Koppa ◽  
Dale L. Picha ◽  
Kay Fitzpatrick

One of the most important requirements in highway design is the provision of adequate stopping sight distance at every point along the roadway. At a minimum, this sight distance should be long enough to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object in its path. Stopping sight distance is the sum of two components–brake reaction distance and braking distance. Brake reaction distance is based on the vehicle’s speed and the driver’s perception–brake reaction time (PBRT). Four separate, but coordinated, driver braking performance studies measured driver perception–brake response to several different stopping sight distance situations. The results from the driver braking performance studies suggest that the mean perception–brake response time to an unexpected object scenario under controlled and open road conditions is about 1.1 s. The 95th percentile perception–brake response times for these same conditions was 2.0 s. The findings from these studies are consistent with those in the literature: that is, most drivers are capable of responding to an unexpected hazard in the roadway in 2.0 s or less. Thus, the American Association of State Highway and Transportation Officials’ perception–brake response time of 2.5 s encompasses most of the driving population and is an appropriate value for highway design.


2019 ◽  
Vol 24 (1) ◽  
pp. 60
Author(s):  
Rizqi Rangga Perdana ◽  
Yeremia Kristian Adi Permata ◽  
Siti Latifah ◽  
Sukoyo Sukoyo ◽  
Wasino Wasino

<p class="Default"><em>Ambarawa – Magelang main road is an arterial road which used by drivers who came from Central Java headed to Yogyakarta. The Road Segment is considered to have frequent traffic accidents. The study aims to analyze the relationship between geometric aspects and the occurrence of accidents, compare actual speed with plan speed, and analyzing the completeness of the traffic signs on this section to identify the causes of accidents that occurred at that location</em>. <em>The stages of analysis is by doing the geometric calculation of the road and compared with the requirements in the regulation then identifying whether there is a relationship between accidents that occur with geometric conditions, vehicle speed, and the signs completeness. Identification and results of geometric analysis is known that Black Spot are on bend road I (km 46+300) there were 22 accidents due to breaking road markings, 6 accidents due to extreme bend, and 4 accidents due to road slackness throughout 2012 – 2018. On the bend road II (km 46+440) there were 5 accidents due to breaking road markings and on the bend road III (km 46+520) there were 3 accidents due to road slackness. with the result that there is a relationship between geometric conditions with accidents that occur and after being analyzed the completeness of the traffic signs is still lacking and needs to be completed.</em></p>


2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Ilya Ovchinnikov ◽  
Rafail Garibov ◽  
Igor Ovchinnikov

The task of the comparative evaluation of the safety lighting poles installed around the road under the action hit them the car. Notes that studies on the calculation and modeling lighting poles when exposed to shock loads due to vehicle collisions is very small. The situation of a conditional vehicle exit (LADAPRIORASEDAN) from the carriageway to the roadside is followed up, followed by a collision with a metal or reinforced concrete support for external electric lighting. Vehicle speed is 60 km/h and the calculation is performed by finite element method. Diagram shows the compressive forces, bending moments, shear forces, displacements. The analysis found that by hitting the conditioned car to support the outer electrical lighting in a bearing of reinforced concrete arise effort close to being admitted that for small deviations from design parameters (e.g., speed limit is exceeded, possible defects and injuries of lighting columns) can lead to the collapse construction, including the possible fall of its vehicle. Consequently, the support of the metal outer lighting when hit by the vehicle conditional security parameters and external lighting strength of reinforced concrete is preferred support.


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