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Communicating Towed unit (Trailer) Vehicle Identification Number(s) (VIN) to the Powered unit.


The primary mission of Federal Motor Carrier Safety Administration (FMCSA)  is to reduce crashes, injuries and fatalities involving large truck and buses. One of the strategies employed to accomplish this goal is to foster innovative research in new or augmenting safety enhancing technologies and to facilitate faster deployment of proven systems. In collaboration with our industry partners and stakeholders, we continuously identify new opportunities of emphasis that can serve our agency goals and objectives towards improving highway safety. The opportunity outlined in this solicitation refers to a challenge that, if addressed robustly and cost-effectively, has the potential to further aid many ongoing USDOT safety, security, mobility and efficiency initiatives.


The Commercial Motor Vehicle freight movement in North America involves powered units (tractors, trucks, buses) that haul a variety of towed units (trailers) in often changing configurations. A sample overview of possible tractor-trailer configurations is outlined in Reference [1]. And due to the fact that the lifetime of a trailer is often much longer than tractors, tractors must work with a variety and age of trailers over the course of their use. To address various roadside, border crossing, smart parking, connected vehicle initiatives, FMCSA  would like to explore robust and very cost effective mechanisms to communicate the trailer(s)’ VIN(s) to the powered unit for some unique opportunities. The composition of the trailer VIN includes a number of trailer characteristics that are defined by NHTSA that can be decoded and used for a variety of reasons.  (More details on Trailer VIN can be found on pages 15-20 in [2].)


FMCSA envisions that trailer VIN information, if transmitted to the tractor can be used in a number of ways to support various ongoing and future initiatives. For instance, by robustly identifying the accurate number of  and characteristics of the attached Trailers, on-board safety systems resident on the tractor can be further optimized for performance.

FMCSA’s Wireless Roadside Inspection (WRI) program can use trailer VIN information in the set of data wirelessly exchanged between a roadside unit and the tractor hauling the subject trailer(s). With this mechanism, tractor-trailer configuration at WRI nodes can be properly identified.

Wireless initiatives streamlining Border Crossing processes can use trailer VIN data in their exchange protocols and automatically determine if the attached trailers match the dispatch documentation.

USDOT’s Connected Vehicle Program can use the trailer VIN information to determine the accurate number of hauled trailer units, total combination vehicle length, axle configurations, trailer body types, etc which would aid articulated vehicle handling within the Basic Safety Message (BSM) definitions.


Similarly, decoded trailer VIN information would aid Smart-Park initiatives with the knowledge of the tractor-trailer configuration and total length.

Research Objectives:

The purpose of this topic is to develop cost-effective solutions in the form of devices that can communicate trailer VIN(s) to the powered unit they are connected to. It is foreseen, but not required, that the high level architecture would be composed of a trailer based VIN transmitter and a tractor based VIN receiver and interpreter.

In general, there is little challenge in communicating a trailer’s VIN to the tractor as a technical objective. It can be done wirelessly (Wi-Fi, Dedicated Short Range Communications (DSRC), etc) or over the power line using Power Line Carrier (PLC) protocol (solutions are not limited to these options). The challenge posed in this topic goes beyond the rather trivial ability to communicate a VIN from a trailer unit to a tractor and the Offerors must address these aspects listed below, among others, of the design challenge in their proposals.


The following are the general objectives, requirements and constraints:

1.     Trailer transmitter unit shall be very cost effective. If this project is successful, vision is to support a decision to retrofit every single trailer in the field with a trailer transmitter.

2.     The trailer transmitter units shall be programmed once when placed on the trailer. The tractor receiver unit shall not assume to have any a priori knowledge of the trailers attached to the tractor or how the trailer transmitter units may have been configured.

3.     The driver/operator shall have no input to the proposed system. It shall be entirely automatic.

4.     The primary purpose of the tractor receiver unit is to receive VINs, establish a valid number of VIN stack for the attached trailers to the powered unit and put this information on a databus where other devices can use it (such as the J1939 CAN bus). The Offeror’s shall not spend any time on

a.      Any display units for purposes of displaying such info to the driver,

b.     Any ideas on how such trailer VIN information may be used.

c.      How to decode VINs for meaningful interpretations.

5.     The transmitter/receiver solution shall be able to accommodate the communication of –a minimum of- five (5) unique VINs during a given power cycle (triple trailer combination with two dollies).

6.     It is highly desired (but not required) that the solution have a smart logic to be able to sort the VINs by their proximity to the tractor.

7.     The bandwidth should be smartly used; during the course of the vehicle’s operation VIN communication should not be needed continuously. The Offeror shall propose how to structure the use of bandwidth for this purpose. The general idea is to identify the events when the trailer configuration may be changed after first determination and engage re-communication at those instances.


8.     Particularly if an over the air transmission based solutions (wireless) is proposed, the Offerors shall address

a.      How to mitigate the privacy concerns associated with transmitting VINs.

b.     How to prevent cross talk between surrounding units.

In addition to the above technical objectives, the Offerors are asked to discuss the logistics and governance structure that may be needed to implement their proposed solutions in a large scale deployment scenario. For this purpose, consider the hypothetical scenario where every trailer unit in the field will be retrofitted and every new trailer will be built with this device in the future.  The particular segment of interest that needs the Offeror’s attention is the Trailers that are already in service (not new builds). Offeror shall elaborate how their proposed solution can be streamlined in a way that such a hypothetical mandate can be streamlined and carried out cost effectively and in a timely manner. Please discuss the additional devices, tools, governance structure that may be needed to make this a possibility with the proposed approach.

General concepts that need attention shall include the installation ease and costs; the process of programming the trailer VIN transmitter units (where, when, how, by whom); susceptibility of the units for tampering and/or failure in service; self diagnostics needs and solutions; governance structure that may be needed.

Expected Phase I Outcomes:

Outcomes expected from the Phase 1 include a detailed concept that demonstrates the viability of creating a prototype of the Contractor’s approach that satisfies the attributes described above for Trailer VIN transmission to the Tractor. In addition to the above technical objectives, the Contractor will need to discuss cost-benefit trade-offs, logistics and governance structures that may be needed to implement their proposed solutions in a large scale deployment scenario.

Expected Phase II Outcomes:

Phase 2 efforts include manufacturing and demonstration of a working prototype of the Contractor’s approach of transmitting Trailer VINs to the tractor in a number of combination vehicle configurations including multi-unit cases. Furthermore, a detailed experimental plan for assessing the robustness and accuracy levels of the solutions shall be developed and the process for implementing a retrofit concept shall be demonstrated for ease of installation, programming, verification, deployment, scalability etc. Finally, a scenario based preliminary cost-benefit analysis and/or projections shall be conducted in collaboration with USDOT.

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