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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMCIgLz48L3BhcmFtcz48ZmlsdGVycz48ZmlsdGVyIGZpZWxkPSJpbmRleHRlcm1zIiB2YWx1ZT0iJnF1b3Q7UmVmcmlnZXJhdG9yIHRydWNrcyZxdW90OyIgb3JpZ2luYWxfdmFsdWU9IiZxdW90O1JlZnJpZ2VyYXRvciB0cnVja3MmcXVvdDsiIC8+PC9maWx0ZXJzPjxyYW5nZXMgLz48c29ydHM+PHNvcnQgZmllbGQ9InB1Ymxpc2hlZCIgb3JkZXI9ImRlc2MiIC8+PC9zb3J0cz48cGVyc2lzdHM+PHBlcnNpc3QgbmFtZT0icmFuZ2V0eXBlIiB2YWx1ZT0icHVibGlzaGVkZGF0ZSIgLz48L3BlcnNpc3RzPjwvc2VhcmNoPg==" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Cold chain routing for product freshness and low carbon emissions: A target-oriented robust optimization approach</title>
      <link>https://trid.trb.org/View/2540270</link>
      <description><![CDATA[As consumer demand for fresh products continues to rise, the inefficiencies in cold chain logistics have emerged as a pressing issue, resulting in substantial food waste and compromised product quality. Meanwhile, logistics companies face the dual challenge of reducing costs and carbon emissions while ensuring product freshness. In response to these challenges, this paper proposes a novel target-oriented framework that leverages an underperformance riskiness index to optimize cold chain routing decisions. The primary objective is to minimize the risk of not meeting the target freshness level while accounting for costs and carbon emissions. To address the complexity that arises from stochastic arrival times, a linear decision rule is incorporated into the model. The robust counterpart of the problem is reformulated as a mixed-integer linear programming model, which is then solved efficiently using a Benders decomposition approach. Extensive computational experiments are conducted on realistic instances to evaluate the performance of the authors proposed approach. A comparative analysis with two benchmark models is also performed. The experimental results reveal that their target-oriented robust optimization framework generates high-quality solutions. It effectively reduces both the likelihood and magnitude of violations of the target freshness level, while maintaining relatively low costs and carbon emissions.]]></description>
      <pubDate>Mon, 19 May 2025 15:52:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2540270</guid>
    </item>
    <item>
      <title>The concept of digital twin of electric refrigerated vehicle including a tool for its route planning</title>
      <link>https://trid.trb.org/View/2489016</link>
      <description><![CDATA[The article presents the concept of digital twin of electric refrigerated vehicle that includes optimization tool for its route planning. The authors presented literature analysis that describes digital twins, needed for presented concept. Further, the target groups that can benefit from the implementation of such model were shown. The system description is shown with key parameters for digital twin. The mentioned parameters have been placed in the appropriate modules. Each module and the need for their implementation in the model were presented. Then, the flow of information in the model is graphically shown. The proposed solution allows for the creation of a digital twin of an electric refrigerated vehicle, which allows for constant supervision of the vehicle’s parameters and optimization of its route.]]></description>
      <pubDate>Tue, 28 Jan 2025 14:52:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2489016</guid>
    </item>
    <item>
      <title>Aerodynamic of a refrigerated truck and improvement to reduce its aerodynamic drag</title>
      <link>https://trid.trb.org/View/2240328</link>
      <description><![CDATA[Despite the fact that improving heavy vehicle fuel efficiency has received considerable attention, few investigations have been done on reducing the aerodynamic drag of a refrigerated truck. This study has two objectives; first, the aerodynamic of the refrigerated truck (REF-BSL) is investigated, and second, passive add-on designs to reduce the aerodynamic drag of the refrigerated truck are proposed. Flow structure around the truck at Reynolds number (Re) equals 0.2 × 10⁶ is numerically investigated with a steady-state Reynolds-averaged Navier-Stokes (RANS) simulation with the Shear Stress Transport (SST) k-ω turbulence model. For a refrigerated truck, a high-pressure region at the trailer’s front surface is concentrated at the pocket area between the refrigerator and the tractor. The presence of the refrigerator alters the shear layer at the trailer’s roof as it propagates downstream, causing the saddle point location at the near-wake to shift. The refrigerator installation increases the total drag by 9%, relative to a truck without the refrigerator. Three add-on designs (REF-A, REF-B, and REF-C) positioned at the pocket area are examined to reduce the aerodynamic drag of REF-BSL. The working principle of the add-ons is to re-direct the incoming fluid toward the sides of the truck, preventing the formation of the high-pressure region at the pocket area, thus lowering the total drag of the refrigerated truck. The REF-B design is found to be the most efficient in terms of reducing drag by 16.5%.]]></description>
      <pubDate>Fri, 22 Sep 2023 09:05:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2240328</guid>
    </item>
    <item>
      <title>The electric vehicle promotion in the cold-chain logistics under two-sided support policy: An evolutionary game perspective</title>
      <link>https://trid.trb.org/View/1923797</link>
      <description><![CDATA[Many countries, industries, companies and end consumers have actively switched from fuel cars to electric vehicles (EV) to combat global warming via emission control. However, given cost and research and development uncertainties, refrigerated truck manufacturers (RTMs) and cold-chain logistics enterprises (CCLEs) are hesitant to update and employ electric refrigerated trucks (ERTs). Government support, notably subsidies, is vital in the ERT promotion. Thus, this study investigates the optimal two-sided support policies of the government (i.e. subsidies for CCLEs and RTMs) to explore how it achieves the best incentive for ERT promotion in the cold-chain logistics with limited resources. The study develops an evolutionary game model to analyse the influence of multiple factors on ERT upgrade and penetration strategies, clarify dynamic subsidy policy adjustment measures based on industrial evolution under multiple-factor interactions, and discuss the dynamic adjustment priority of the two-sided subsidy policies. The results indicate that the two-sided hierarchical subsidy policy can improve the promotion of ERTs and stimulate the electrification development of the cold-chain transportation industry. Finally, the decision-making preferences of RTMs and CCLEs in multiple scenarios are discussed and feasible management suggestions for government and enterprises are proposed accordingly.]]></description>
      <pubDate>Mon, 28 Mar 2022 10:37:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1923797</guid>
    </item>
    <item>
      <title>The impact of trailer conditions on the quality of refrigerated food transport services – A case study</title>
      <link>https://trid.trb.org/View/1690399</link>
      <description><![CDATA[The carriage of food products, in particular fresh products, is particularly sensitive to transport conditions. The aim of this paper is to examine the effect of trailer conditions on the quality of refrigerated food transport services. Six wireless measuring devices installed permanently in 3 trailers were used for the analysis. The built-in transmitter sensors have enabled the collection of data in the areas of temperature, humidity, pressure, shock and light intensity. Monitoring parameters via a wireless device can contribute to the reduction of fuel costs in the enterprise, e.g., detection with vibration sensor / acceleration of aggressive driving style of the driver causing suspended fuel consumption, detection of inappropriate transport conditions, etc. Analysis of the test results showed that in the same trailer the product distribution is very important owing to the different temperature. The analysis carried out showed that in the middle of the semitrailer, i.e. in the place where the breeze is located, temperature fluctuations amount to 5°C, which indicates a greater risk of loss of quality of the transported products.]]></description>
      <pubDate>Thu, 23 Apr 2020 15:58:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1690399</guid>
    </item>
    <item>
      <title>Effect of humidity on condensation in vapour compression refrigeration system for fresh food transport vehicles</title>
      <link>https://trid.trb.org/View/1573676</link>
      <description><![CDATA[In today's world the developed countries rely on the refrigerated container (reefer) vehicles for the transportation of cold chain products such as fresh foods. In India this technology was introduced in late 1980s but the growth was very slow compared to other countries and failed to match the international trends. However recently, with fast development of roadways, urbanisation and connectivity the reefers get a massive response. The reefers have several advantages but they consume considerable amount of electrical energy to operate. Reefer works based on vapour compression refrigeration cycle in which condenser is an important device. This condenser uses fan-blown atmospheric air over it to remove vaporization heat from refrigerant. The temperature of refrigerant after condensation has effects on Coefficient of performance (COP) of the refrigeration system. This temperature can be altered by the relative humidity of air. The result of the authors' project shows that the increase in air humidity by 18.60% increases the COP by 11.37% and also it reduces the power consumption.]]></description>
      <pubDate>Fri, 28 Dec 2018 14:01:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1573676</guid>
    </item>
    <item>
      <title>Thermodynamic Cycle Analysis of Mobile Air Conditioning System Using Hydrofluoroolefin (R1234yf and R1234ze) As an Alternative Refrigerants to R134a</title>
      <link>https://trid.trb.org/View/1478815</link>
      <description><![CDATA[This paper presents a thermodynamic cycle analysis of mobile air conditioning system using hydrofluoroolefin (R1234yf and R1234ze) as an alternative replacement for R134a. The analysis evaluates performance on simple VCS under various working conditions (varying condensing temperature and evaporating temperature, subcooling, superheating with and without internal heat exchanger (IHX). R1234ze requires high pressure ratio and high theoretical displacement and for that there must be a heavier engine and the authors cannot retrofit with R134a refrigerant so they selected R1234yf for comparison with R134a. The energy performance parameters of R1234yf are close to those obtained with R134a at low condensing temperature and making use of an IHX. Even though the values of performance parameters for R1234yf are smaller than that of R134a, but difference is small so it can be a good alternative to R134a because of its environmental friendly properties with introducing IHX.]]></description>
      <pubDate>Wed, 27 Sep 2017 10:20:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1478815</guid>
    </item>
    <item>
      <title>Development of the Large Type Electric-Driven Refrigerator for the HV Truck</title>
      <link>https://trid.trb.org/View/1461909</link>
      <description><![CDATA[In respect to the present large refrigerator trucks, sub-engine type is the main product, but the basic structure does not change greatly since the introduction for around 50 years. A sub-engine type uses an industrial engine to drive the compressor, and the environmental correspondence such as the fuel consumption, the emission is late remarkably. In addition, most of trucks carry the truck equipment including the refrigerator which consumes fuel about 20% of whole vehicle. Focusing on this point, the following are the reports about the system development plan for fuel consumption reduction of the large size refrigerator truck. New concept is to utilize electrical power from HV system to power the electric-driven refrigerator. We have developed a fully electric-driven refrigerator system, which uses regenerated energy that is dedicated for our refrigerator system. It is the world’s first new concept to use the all electricity that regenerated by HV system for the drive of our electric refrigerator, not only for a run assist. Not limited to the high quality and stability refrigerator performance, it also realizes the reduction of the fuel and noise during the freezing operation. Fuel consumption reduced due to light weight drive system by replacing the heavy sub-engine to an electric compressor and also elimination of additional fuel line for sub-engine. Also, the maintenance expense can decrease because of the simple drive system and piping layout. By the all-in-one unit structure which is integrated an electric compressor close to the evaporator and condenser, the refrigerant piping is largely shortened and the efficiency and the reliability of the refrigerator are improved. We have proven that the system is able to save fuel consumption up to 64% by applying new control system which considers cooperation with the vehicle hybrid control system.       ]]></description>
      <pubDate>Mon, 25 Sep 2017 14:09:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1461909</guid>
    </item>
    <item>
      <title>Next-generation Ejector Cycle for Truck-transport Refrigerator</title>
      <link>https://trid.trb.org/View/1430597</link>
      <description><![CDATA[The development of energy-saving technologies is in great demand recently to stop global warming. We are committed to developing the Ejector Cycle as an energy-saving technology for refrigerating air conditioners. The ejector, which is an energy-saving technological innovation, improves the efficiency of the refrigeration cycle by effectively using the expansion energy that is lost in the conventional steam-compression cycle, and is applicable to almost all steam-compression refrigerating air conditioners, thus improving the efficiency of the refrigeration cycle. Concerning the application of the Ejector Cycle in truck-transport refrigerators, we previously released Ejector Cycle products for large and medium-size freezer trucks, which have been favorably accepted by custom-ers.         We attempted to develop a new Ejector Cycle for application in compact refrigerators, and succeeded in completing a commercial compact refrigerator incorporating a next-generation Ejector Cycle that substantially improves performance. This paper introduces the development.       ]]></description>
      <pubDate>Wed, 23 Aug 2017 15:56:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1430597</guid>
    </item>
    <item>
      <title>A Study of Thermoacoustic Refrigerator</title>
      <link>https://trid.trb.org/View/1461924</link>
      <description><![CDATA[A diesel engine is advantageous in its high thermal efficiency, however it still wastes about 50% of total input energy to exhaust and cooling losses. A feasibility study of thermoacoustic refrigerator was carried out as one of the means to recuperate waste heat. The thermoacoustic refrigerator prototyped for this study showed a capability to achieve cooling temperature lower than -20 degree C, which indicated that the system has a potential to be used in refrigerator trucks not only for cargo compartment cooling but also for cabin cooling.       ]]></description>
      <pubDate>Tue, 01 Aug 2017 10:08:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1461924</guid>
    </item>
    <item>
      <title>Development of a Fuel Consumption Test Procedure for Refrigeration Units</title>
      <link>https://trid.trb.org/View/1432690</link>
      <description><![CDATA[This project's objective was the development of a test procedure to evaluate the impact of the refrigerated van box on the fuel consumption of the refrigeration unit. The scope of the project included a review of the test procedures, the development of a testing methodology for measuring the fuel consumption of the refrigeration unit on a specific duty cycle, and testing with a view to validating the methodology.         Road and track tests are subject to variations in conditions, and controlling or accounting for these variables as much as possible is an important part of ensuring accurate results. However, when testing a refrigerated van on the track or on the road, it is very difficult to eliminate variable external influences and to isolate the particular influence of the refrigerated van on the refrigeration unit's fuel consumption. For this reason, tests were conducted in an environmental chamber in controlled temperature and humidity conditions.         Validation tests took place in an environmental chamber at an ambient temperature of +32°C. The refrigerated box had an interior temperature of -10°C. The tests aimed to compare the fuel consumption of the same refrigeration unit installed on the same test vehicle, but with two different refrigerated van boxes. The first refrigerated box had a classic design, with aluminum and steel joints and insulated with spray-on urethane foam, whereas the second unit had a newer design, using high-density polyurethane sandwich panels, and without any internal or external metal joints, which eliminate thermal bridges promoting heat transfer.         The tests showed that it is feasible to conduct fuel consumption tests in an environmental chamber to evaluate the fuel consumption of a refrigeration unit, and the repeatability of the tests can be ensured. The tests resulted in 9.6% ± 1.8 % fuel savings with the newer deign refrigerated box, when compared with the classic design refrigerated box.       ]]></description>
      <pubDate>Mon, 17 Jul 2017 09:32:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1432690</guid>
    </item>
    <item>
      <title>New refrigerants on the way : transport refrigeration units will soon be subject to tighter regulations on the use of hydrofluorocarbon refrigeration</title>
      <link>https://trid.trb.org/View/1468991</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 01 Jun 2017 10:17:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468991</guid>
    </item>
    <item>
      <title>Reefer fleets face added complexity under food safety rule, McLeod says</title>
      <link>https://trid.trb.org/View/1425176</link>
      <description><![CDATA[]]></description>
      <pubDate>Tue, 04 Oct 2016 11:27:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1425176</guid>
    </item>
    <item>
      <title>Simulation-based Concept Study of the Efficiency Gain Using a Hybrid-electric Refrigerated Vehicle with an Electrically Operated Cooling System for Urban Freight Transport</title>
      <link>https://trid.trb.org/View/1423463</link>
      <description><![CDATA[In the pursuit of higher energy efficiency, reduced usage of fossil fuels and lower emissions in urban areas, hybrid vehicle technologies are a promising basis for the transportation of refrigerated goods. The goal of the project, described in this contribution, is to develop a refrigerated vehicle for the delivery of goods in urban areas and to design an optimized operating strategy based on hybrid electric technology. The electrically operated cooling system will be powered by the traction battery of the hybrid vehicle. Independent of the vehicle’s operating mode, the electric energy is always generated at high efficiency. Even in idle periods, or during stop-and-go traffic, full cooling performance can be delivered continuously. The design and optimization will be conducted by a multiphysical simulation of the entire vehicle including all relevant cooling components. This paper describes the development of a Toyota hybrid vehicle model and the implementation and validation of the operational strategy of the considered vehicle. Efficiency and power of the vehicle are calculated using efficiency maps of the internal combustion engine and the two motor generators. Measured real-life driving cycle data of a company, which distributes fresh organic vegetables and food in Vienna directly to the customer, will be used to compare the performance of the new vehicle concept with ordinary diesel driven refrigerated vehicles. The proposed hybrid refrigerated vehicle enables significantly higher energy efficiency than the ordinary system. This can be explained by the advantages of a hybrid electric vehicle itself, especially in the setting of urban traffic. Furthermore, the energy generation for the cooling system always works at highest efficiency of the internal combustion engine due to the operating strategy of the hybrid system. The decreased environmental impact and fuel cost savings of the proposed system will be quantified using the developed simulation model.]]></description>
      <pubDate>Wed, 21 Sep 2016 14:44:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1423463</guid>
    </item>
    <item>
      <title>Reefer technology's becoming more important</title>
      <link>https://trid.trb.org/View/1409893</link>
      <description><![CDATA[Maintenance and monitoring of temps, real-time tracking of trailers and loads, and clean-burning diesels are already here. More new refrigerants are next.]]></description>
      <pubDate>Wed, 01 Jun 2016 13:50:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1409893</guid>
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