Transportation of hazardous materials ( hazmat ) a literature survey Tehlikeli maddelerin taşınması-bir literatür taraması

Öz Transportation has a great role in logistics. Many researchers have studied on transportation and vehicle routing problems. Transportation of hazardous materials (hazmat) is a special subject for logistics. Causalities due to the accidents caused by trucks carrying hazardous materials will be intolerable. Many researchers have studied on risk assessment of hazmat transportation to find ways for reducing hazardous material transportation risks. Some researchers have studied routing of hazmat trucks. The emergency response models and network design problems for hazmat transportation were also studied by some researchers. The transportation of hazmats can also be classified according to the mode of transport. Mainly roads are used for hazmat transportation but some shipments are intermodal. There has been a great amount of effort spent to find convenient ways for hazmat transportation. In this study, a literature survey for the articles about hazmat transportation is prepared. After pointing out the importance of hazmat transportation by the example of US hazmat transportation data, the studies on hazmat transportation since 2005 have been examined. Totally 88 articles are classified as risk, routing, routing and scheduling, emergency response, network design and accident analysis. What can be studied in future researches is pointed out. Taşımacılık lojistik sektöründe çok büyük öneme sahiptir. Birçok araştırmacı taşıma ve araç rotalama problemleri üzerinde çalışmıştır. Tehlikeli maddelerin taşınması lojistik sektöründe özel bir konudur. Tehlikeli madde taşıyan araçların yaptıkları kazalara bağlı olarak meydana gelen ölümler tolere edilemez sonuçlara yol açar. Birçok araştırmacı, tehlikeli madde taşımacılığındaki taşımacılık riskini düşürmek için risk değerlendirme modelleri üzerinde çalışmışlardır. Bazı araştırmacılar ise tehlikeli madde taşıyan araçların rotalanmasını çalışmışlardır. Acil müdahale modelleri ve şebeke tasarım modelleri de bazı yazarlar tarafından çalışılmıştır. Tehlikeli madde taşımacılığı taşımacılık moduna göre de sınıflandırılabilir. Genellikle karayolları tehlikeli madde taşımacılığında en çok tercih edilir fakat bazen karma taşımacılık da kullanılabilir. Tehlikeli madde taşımacılığı için uygun yollar bulma konusunda önemli çabalar sarf edilmektedir. Bu çalışmada, tehlikeli madde taşımacılığı konusunda yazılmış makalelerin bir literatür araştırması yapılmıştır. Amerika Birleşik Devletleri örneği verilerek tehlikeli madde taşımacılığının önemi üzerinde durulduktan sonra tehlikeli madde taşımacılığı konusunda 2005 sonrası yapılan çalışmalar incelenmiştir. Toplam 88 makale risk, rotalama, rotalama ve çizelgeleme, acil yardım, şebeke tasarımı ve kaza analizi olarak sınıflandırılmıştır. Müteakip çalışmalarda nelerin üzerinde durulması konusu belirtilmiştir.


Introduction and general information
Hazardous materials are defined as any substance or material capable of causing harm to people, property and environment [1].In some articles hazmat is also called as dangerous goods.United Nations sorts dangerous goods into nine classes according to their properties.These classes are [2]: Explosive substances and articles, 2 Gases, 3 Flammable liquids, 4.1 Flammable solids, self-reactive substances and solid desensitized explosives, 4.2 Substances liable to spontaneous combustion, 4.3 Substances which, in contact with water, emit flammable gases, 5.1 Oxidizing substances, 5.2 Organic peroxides, 6.1 Toxic substances, 6.2 Infectious substances, 7 Radioactive material, 8 Corrosive substances, Miscellaneous dangerous substances and articles.
The rulers in countries and the carriers must take a special care for transporting hazmats.
The difference between transportation of hazmats and transportation of other goods arises from an accident.
When an accident occurs then the harm to population and environment will be inevitable.Although it is vital to keep information of hazmats only few countries have special departments for transporting hazmats.These departments also keep a database for all hazmat incidents and their results.
Figure 1 shows the distribution of accidents by hazmat class in 2013 in USA according to information of PHMSA-US Department of Transportation Pipeline and Hazardous Materials.The figure illustrates that the majority of the accidents/incidents are flammable-combustible liquids incidents.
In 2013, there were 15919 total incidents resulting 28 hospitalized and 132 Non-Hospitalized injuries.Unfortunately there were 12 fatalities and 81,365,866 dollars damages caused by these incidents [3].Hazmat transportation is a special issue.Therefore the countries restrict the transportation of hazmats by some laws.The European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) was done at Geneva on 30 September 1957 under the auspices of the United Nations Economic Commission for Europe, and it entered into force on 29 January 1968 [2].
The countries have adopted their hazmat transportation according to ADR.
Hazmat transportation is possible via all transportation modes (air, highway, railway, water and pipeline).Mainly hazmats are transported by road and most of the incidents caused by vehicles carrying hazmats resulting fatalities, injuries and environmental damage.If an accident cause hazmat release from the vehicle, then these accidents are called as incidents.
Table 1 shows the number of incidents and fatalities by transportation mode in USA between the years 2007-2013.
Hazmat transportation is very important with respect to economic concerns.Incidents caused by hazmat transportation only in USA caused 548,698,727 dollars damage for last seven years.The damage amounts of last seven years in USA can be found in Table 2.
Hazmat incidents not only cause fatalities and environmental damage, they also cause explosions, fire, vapor dispersion etc.The emergency teams should pay special attention to decrease side effects of hazmat incidents.Sometimes, the need to evacuate the region also is required.Table3 shows hazmat incident results in 2013 in USA.
One can understand from the figures and tables above that, hazmat transportation is a special topic of countries in which hazmat transportation has vital effects.Vehicles carrying hazmat caused accidents resulting fatalities and environmental damage mainly.Hazmat transportation has many side effects when it is examined within the framework of economy.For all these reasons mentioned before, many researchers have published articles with the subject of hazmat transportation since early 1980s.The hazmat transportation did not lose its popularity as the years passed and many researchers still go on to study hazmat transportation.
In the following parts of this study, the hazmat literature review is explained and then details of the hazmat classification are given.

Hazmat literature review
The special importance of hazmat transportation forces the researchers to study on how to decrease risk or which route is the best for hazmat transportation.The researchers also searched the emergency response models and evacuation methodologies after hazmat accidents.In this study, 88 articles published in refereed journals between 2005-2014 (January-March) are examined.Figure 3 shows the number of articles with respect to publication years.Risk of a road was calculated by Erkut as edge risk and path risk.Risk has been main concern of articles about hazmat transportation.
Risk is the most popular item studied by majority of the authors dealing with hazmat transportation.For the recent studies; Toumazis and Kwon, [5] studied on minimizing the risk experienced by the hazmat shipment transportation in any given time-dependent; Chakrabarti and Parikh, [6] prepared a risk-based study of route evaluation, Saat et al. [7] proposed a quantitative analytical approach to estimate the risk cost of transporting hazardous materials by rail and Cappanera and Nonato, [8] focused on how to efficiently compute the Pareto frontier given by the non dominated solutions with respect to total risk and total cost on realistic instances taken from the literature.

Routing
Routing of vehicles carrying hazmat has been the second main concern of the articles about hazmat transportation.From early 1980s to 2014, the researchers have studied on routing the hazardous materials and they mainly focused on local-global routing, transportation mode, vehicle type, single-multi commodity, single-multi objective routing of hazmat transportation.
Traditionally, main consideration for hazmat transportation was about cost and safety [9].Therefore for routing hazmat vehicles while carriers are trying to decrease their transport cost, local or global authorities should care about the safety of population.
For the recent studies on routing hazmat; Samanlioglu, [10] proposed a multi-objective mathematical model for the industrial hazardous waste location-routing problem, Desai and Lim, [11] focused on a stochastic dynamic programming approach for hazardous material route selection problem and Mahmoudabadi and Seyedhosseini, [12] dealed with the principle of hazmat routing problem and fundamental concerns of chaos theory for defining dynamic variables are combined to develop a mathematical model while risk and time are prioritized by corresponding coefficients.

Routing and Scheduling
The carriers and governments must have some strategies in order to reduce transport risk.Time of the transportation is important.Government and local authorities serve as supervisor to hazmat carriers and, they allocate road segments or available population zones within a time period [13].The carriers should route and schedule their hazmat vehicles according to restrictions of the authorities to minimize transport risk.

Emergency response
After a hazmat incident, it is obvious that emergency response is crucial in order to decrease or minimize the effect of incident.To establish a hazmat emergency response system constitutes a building block toward a comprehensive public and environmental safety infrastructure [14].Emergency response departments are fire-fighting departments, first-aid teams and police stations [15].The articles for emergency response are few when it is compared with risk and routing.One of the main concerns of emergency response researches is to locate response departments to best places in which the risk of the link is highest.

Network design
Network design is mostly popular in transportation and communication.Network design has different characteristics in the context of hazmat shipments.The transportation infrastructure is built mainly to connect heavily populated areas and not to avoid them.Therefore, the question becomes which road segments to close in an existing network rather than identifying the most appropriate ways to expand the infrastructure Erkut et al. [1].Designing hazmat transportation is first introduced by Kara and Verter [16].They proposed a bilevel integer programming model for network design.They considered the problem with two sides: government and carriers.The objective was minimizing risk while considering the carriers concern about minimizing cost.After Kara and Verter [16], Erkut and Alp [17] proposed an "optimum communication spanning tree problem" to design a network for hazmat shipments.Bianco et al. [18] introduced a bi-level network flow model, and Xu et al. [15] considered the network design with emergency response together under complex fuzzy environment.

Accident analysis
The accident analysis is a must in order to understand the effects of hazmat incidents.However, few articles are published about accident analysis of hazmat vehicles.Ronza et al. [19], used transportation accident databases to investigate ignition and explosion probabilities of flammable spills.Ghazinoory and Kheirkhah [20] was focused on transportation risk as the main parameter and they developed strategies for reaching the optimal condition and they laid out the impacts of these strategies on the reduction of accidents are analyzed.There are 13 articles published in refereed journals between 2005-2014 about accident analysis and main concentration of these articles is to analyze accidents in order to decrease the risk of hazmat transportation.
Figure 5 shows the number of articles published between 2005-2014 which are classified according to main subject studied in the articles.To make a better understanding of the articles we prepared Table 4 which shows the publication year, author, and name of the article, topic and methodology used in the article.Table 4 provides the classification of articles using the above six main subjects.The 39 of articles over 88 articles deal mainly with risk of hazmat transportation.26 of the articles take into consideration the routing of hazmat vehicles mainly.In 6 articles emergency response, in 6 of articles network design and in 13 articles accident analysis are studied.Since in some articles two subjects are studied at the same time, total numbers of the articles which are classified are not 88 in Figure 5.The methodologies which are used in each article are also shown in Table 4.
Transportation of hazardous materials in Iran: A strategic approach for decreasing accidents

Accident analysis
Strategies for reaching the optimal condition are laid out and the impacts of these strategies on the reduction of accidents are analysed.28 Verter and Kara [43].
A path-based approach for Hazmat transport network design

Network design
The main modelling construct in this paper is a set of alternative paths for each shipment that is mutually acceptable to the government and the hazmat carriers involved.We discussed the use of the maximum cardinality of alternative path sets K and the maximum allowable percent detour from the shortest path D as possible means of constructing the alternative path sets 29 Trépaniera et al [44].

Cross-analysis of hazmat road accidents using multiple databases
Accident analysis Cross-analysis of databases

Accident analysis
The spatial distribution, the causes and consequences of the accidents related to the population (e.g., number of people killed, injured, evacuated, or poisoned), and environment elements were analysed 46 Milazzo et al [60].
A study of land transport of dangerous substances in Eastern Sicily Risk (risk assessment, risk reduction, risk analysis, etc.) The application of TRAT-GIS code to the land transport of hazardous materials  Routing hazardous materials on time-dependent networks using conditional value-atrisk Routing A numerical method to determine an optimal departure time and an optimal route for a given origin-destination pair

Conclusion
Hazmat transportation is a crucial subject since the incidents caused by vehicles carrying hazmat resulted in huge amount of fatalities and environmental damage.Despite its importance, few countries take serious steps towards hazmat transportation risk and only these few countries have special departments about hazmat transportation.
Hazmat transportation has attracted the attention of researchers since early 1980s and it did not lose its popularity since then.Erkut et al. [1] prepared a chapter about hazmat transportation and one can found the hazmat transportation related articles literature review between 1982-2004 in that chapter.
In first part of our study, we figured out the importance of hazmat transportation with respect to fatalities and economical concerns.In second part, we prepared a literature survey about the hazmat transportation articles since 2005.88 articles are examined in details, and the articles are classified according to publication year, hazmat class and the main concern of the article.Short briefs about risk, routing, routing and scheduling, network design, emergency response and accident analysis were given.We add two different subjects (emergency response and accident analysis) to Erkut et al.'s [1] classification since these two subjects have begun to be popular among authors who study hazmat transportation.At the end of our study, all the articles are given in a table according to 6 classification subject.
For the future works, the articles can be classified according to new study areas of the authors dealing with hazmat transportation.We also propose that every classification can be a unique subject to the researchers.Thus, authors can explain the subject in detail which helps to understand methodologies in the articles deeply.The articles which are published in journals are examined in this study.Future researchers can study on the books, websites, and conferences regarding hazmat transportation.

Figure 2 :
Figure 2: Number of hazmat-transportation related papers published in refereed journals between 1982-2004.The articles can be classified in many ways.One of the classifications made by Erkut et al. [1] is;  Risk assessment,  Routing,  Combined facility location and routing,

Figure 3 :
Figure 3: Number of hazmat-transportation related papers published in refereed journals between 2005-2014.

Figure 4 :
Figure 4: Number of papers related to hazmat class carried.

Figure 5 :
Figure 5: Number of papers according to main subject studied in the article.

Table 1 :
Incidents and fatalities by transportation mode and incident year.

Table 2 :
Damage amounts ($) by mode and incident year.

Table 3 :
2013 Hazmat incident results in USA.

Table 4 :
A classification of hazmat transportation articles.

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)

Table 4 :
A classification of hazmat transportation articles.(et seq.)