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This paper presents an on-board instrumentation to evaluate articulated vehicle maneuvers, using a system that combines a set of sensors and a GPS receiver with custom-made evaluation software. This system allows evaluating vehicle maneuverability and the performance of the truck's driver in real time. Also the performance measures and test maneuvers are briefly described.

One of the main concerns in road conservation and maintenance activities is the interaction between tire and road through the contact patch. The internal air pressure and the weight supported by the tire are factors that affect the force and pressure transmitted to road surface by the vehicle. An experimental study related with load distribution and pressure in the tire's contact patch is presented in this paper. For testing, a lab prototype was used to determine the static load distribution along and transversally to the tire's contact patch. Two types of tires, both for light trucks, were used: one single radial and the other bias-ply, this last type in dual configuration. Several combinations of vertically supported load and air pressure were applied to testing tires. Results showed that contact pressure is uneven in the contact patch and lower than air pressure for the radial tire, but in some cases higher for the bias-ply tires in dual configuration.

Trucks with semi-trailers are widely used for transportation of goods due their low operation cost, but inherent to these vehicles are some problems such as a poor maneuverability. To minimize the effects of this disadvantage, among other solutions, the incorporation of steerable axles in the semi-trailers has been proposed. This paper presents a steering equation, and a fuzzy-logic controller for a semi-trailer automatic forced-steering system to minimize the off-tracking and the total swept path width, resulting in an improvement of vehicle's maneuverability at low speeds. To accomplish this, the suggested control algorithm considers the articulation angle, and parameters such as vehicle speed and direction. The system was tested on an instrumented experimental semi-trailer during various predetermined test maneuvers.

The tractor-trailer combination is one of the articulated vehicular configurations for road cargo transportation most widely used. Due to the length of these articulated vehicles and the coupling geometrical characteristics, they undergo poor maneuverability. In order to obtain a better understanding of the maneuverability, this paper deals with an experimental one-axle semi-trailer coupled to a light duty pick up truck being used to perform some low speed maneuvers. These test maneuvers include stationary and transient turns, as well as slalom type ones, performed while the semi-trailer axle is set directionally straight or steerable. During each maneuver condition, parameters as planar articulation angle, tractor and trailer yaw rates, and the correspondent steering angles were measured.

The relationship between road geometric design and vehicles moving along it should be in a harmonic way in order to reduce the risk of accident occurrence. As a safety issue, the accident black spot analysis can lead to improvements in traffic signaling and/or to changes to the conflictive roadway section. This paper shows the applicability of the vehicle's dynamic behavior simulation as a complementary tool for evaluating geometrical modifications of roadway sections. A simplified example is described using a typical heavy vehicle, which follows a roadway section under two scenarios, one with an unchanged path and other with some modifications in order to increase safety. Results showed that vehicle's dynamic simulation can offer a detailed perspective of the vehicle's behavior to identify the effectiveness of the proposed changes before they are applied in the practice.