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Federal Motor Carrier Safety Administration (FMCSA)


The primary mission of Federal Motor Carrier Safety Administration (FMCSA) of Department of Transportation (DOT) 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 high potential to further improve the efficacies of existing safety technologies.


In North America, the powered heavy trucks often haul a variety of towed units during their operation. As a reference, some of the common combination vehicle configurations can be found on page 26 (Figure 7) of the TRB publication "Trucking 101" [1]. 
In most cases, the combination vehicles are not "married couples", i.e., the tractor and the trailer(s) do not stay coupled through the life span of the vehicles. The common Commercial Motor Vehicle (CMV) operation involves a tractor to haul different trailers as often as in each trip.

Furthermore, the typical lifecycle of a trailer is much longer than that for a tractor. There are operational and economic reasons leading to these market dynamics, but the important ramification of this fact is that tractors often have to haul a wide variety of old and new trailers with substantially differing characteristics. And there is little-to-no information available to the tractor as to what is being towed (that can be automatically detected without driver input).

This solicitation calls for innovative solutions to automatically identify some trailer attributes from within the tractor (powered unit). These attributes of interest will be discussed in further details later on.


On-board safety systems on newer tractors are capable of providing enhanced safety margins for combination CMVs under a wide variety of operating conditions. Such systems include Electronic/Roll Stability Control, Adaptive Cruise Control and Crash Imminent Emergency Brake Assist, among others. They operate with nominal assumptions on the trailer characteristics. The need for these assumptions limits developers' ability to further optimize their safety systems' performances. Hence, there is substantial potential to improve efficacies of such on-board safety systems if there were a mechanism to automatically determine certain trailer characteristics from within the tractor in a robust manner without the reliance on the operator to be in the loop. Automatic detections need to be convertible into electrical signals that can be communicated via the vehicle database to these safety systems.

Furthermore, the ability to know the vehicle combination type and the associated attributes of the trailer(s) at the tractor has the potential to simplify mobility applications such as Truck Parking initiatives (where parking reservation systems can be more optimally carried out if the combination vehicle characteristics are known) and to improve implementation efficacies of connected vehicle applications such as Vehicle-to-Vehicle (V2V) safety functions where one of the V's in the interaction is a combination vehicle with unique characteristics.


This solicitation calls for innovative solutions to identify some trailer attributes from within the tractor. Some trailer attributes of interest are the following and the proposed solution shall address at least a subset of the high priority attributes (as defined within the context of this solicitation) on this list:

High priority attributes:

  • The number of trailer units being towed,
    • An accurate determination of whether the combination vehicle is a tractor-semi, tractor –double trailer or tractor-triple trailer (at a minimum, differentiate between semi and multi-trailer cases),
  • The existence/nonexistence of (functioning) trailer ABS on (each of) the towed unit(s),
    • An accurate determination of whether a functioning ABS system is existent on each of the hauled trailer units.

Secondary attributes of interest are:

  • The length of the trailer unit(s) (or the aggregated trailer train length),
  • The number of axles and their potential locations (configurations of) on the trailer(s),
  • Trailer height,
  • Trailer type, and/or load type.

The proposals can list capabilities of determining other trailer attributes for consideration as well. Such propositions need to explain why those factors would be important to vehicle and traffic safety. Proposers shall research and be aware of existing mechanisms to determine certain characteristics and identify the unique benefits of their propositions while keeping current means in perspective. For instance, using mass estimation algorithms and hard coded bobtail weight specifications of a tractor, it is possible to reliably determine if a trailer is connected to the tractor or not. That same mechanism also can help determine the total weight of the trailer but cannot tell what the weight difference is between the trailer and the load or how many trailers may be connected at any given time.

Requirements for the Research:

The vision for this solicitation is that the concept system will be fully decentralized and be resident on the tractor. It can be assumed that such a system will be installed on new tractors only (i.e. it will not be retrofitted on older tractors in the field). Since one of the primary objectives of this study is to improve efficacies of the listed commercially available technologies, the proposers can assume the existence of them on the tractor.

The summary of the constraints associated with the Phase I work are the following.

  • The proposed solution shall be hosted solely on the powered unit (tractor), i.e., the proposed solution shall not depend on the existence or non-existence of non-standard components on the Trailers and shall not require installation of anything new (on the Trailers).
    • While the above requirement is ultimately desired, practical solutions requiring very rudimentary modifications to the trailer units may also be considered, however, they should be very easy to install and very cost effective. Furthermore, if a modification to the trailer is proposed as part of the solution, a section should be dedicated in the technical approach section describing why high volume costs (component, installation and maintenance costs) would be considered cost-effective and feasible keeping the pool of existing Trailers in the field in perspective.
  • There should be no additional connections required to the trailers except for the common connections such as the 7-pin electrical connector and the pneumatic connections between the powered and towed units (via the gladhands ),
  • The solution shall work with all new and legacy trailers without a priori knowledge on the trailer attributes,
  • The solution shall not rely on the operator's action or inaction,
  • The solution shall not rely on the existence of or communication to a road-side equipment or require for new infrastructural changes,
  • The determination accuracy shall be documented and be better than 2-sigma level (95.5%) in correctly identifying each subgroup within a given characteristics,
  • The solution could depend on a reasonable learning period where estimation logic may need to take its course. However, the system shall provide a confidence metric and converge to a highly reliable determination within a reasonable amount of time. An example "reasonable time" would be from the vehicle power-up event to the vehicle reaching 20mph speed for the first time. This is not a golden rule but an example that can be used as guidance. Proposals that depend on a "learning period" shall discuss the reasonableness of the convergence requirements.

Research Plan:

The proposers should outline a sound technical approach that can address at least a subset of the trailer attributes classified as "high priority" within the context of this solicitation. Phase I work should result in a proof of concept for the proposed trailer attribute determination system. 
During Phase II, the system will be developed to demonstrate the capability at the desired accuracy levels on real vehicles and a risk assessment plan will be carried out to address the potential failure modes and the corresponding ramifications for the intended uses of this solution.

Targeted Technology Readiness Level (TRL) for Phase I is "Basic Technology Research" (TRL 1 & 2) and "Research to Prove Feasibility" (TRL 2 & 3).


  • Roadside based solutions are NOT part of this solicitation. There is other research being carried out where trailer attributes can be measured via external devices and wirelessly communicated to the vehicle. Such proposals to this solicitation will not be considered.
    • Examples of such work are TDS Model 110 [3] and TDS Model 230 [4], as well as another SBIR 11.1 FH3 (closed). [5]
  • The accuracy desired for the determination of the number of connected trailer units is 6-sigma level (99.9997%). However, projected accuracies of 2-sigma (95.5%) or better would be considered for Phase I evaluations [accuracy is implied for each subgroup characterization].
  • Camera based solutions are often not well suited for this kind of research. While such technologies are not excluded from consideration, a proposer leveraging camera-based technologies shall address the common shortcomings of such technology such as their impairment by inclement weather, surface reflections, lens contamination, background interference, among others.
  • Since existing connectivity between the tractor and the trailer(s) take place over the power line and the pneumatic line, the prospective proposers are encouraged to attempt to further leverage these mechanisms in conjunction with recent advances in electronics, computing, acoustics and nano-technology among others. An example technology that leverages power-line connectivity is power line carrier (PLC) for trucks [2].
  • If the proposed technology is susceptible to vibration, the proposal should address how the technical approach will handle cab suspension.
  • The proposers are responsible to investigate and disclose all trademarks, licensing needs and intellectual property rights that may be in place in relation to their proposals.
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