U-turn lanes eliminate left turns at intersections and allow the manoeuvre to be made via median crossovers beyond the intersection. However, there are many situations where road infrastructures are characterized by the reduced width of the median. It is clear that, in such situations, we must adopt design criteria that take into account limitations imposed by the width of the cross-section of the road. This is the reason why it is necessary to adopt design solutions which expect a complete reorganization of the road section affected by the insertion of U-turns. In this paper, we intend to propose original guidelines for U-turn lane design, suitable to guarantee both the necessity to offer a high level of functionality of the road sections to be implemented by U-turns, and the principles of safety in order to reduce unsafe conditions during inversion manoeuvres as much as possible.
The musculocutaneous nerve (C5–C7) is a terminal branch of the lateral cord of the brachial plexus and provides motor innervation to the anterior compartment of arm muscles. Both the musculocutaneous and median nerve may show numerous anatomical variations. Keeping in mind possible aberrations in the course of the upper limb nerves may increase the safety and success rate of surgical procedures. The presented report is a detailed anatomical study of the fusion between the median and musculocutaneous nerve, supplemented by intraneural fascicular dissection. In the presented case, the musculocutaneous nerve was not found in its typical location in the axillary cavity and upper arm during the preliminary assessment. However, a careful intraneural fascicular dissection revealed that musculocutaneous nerve was fused with the median nerve and with its lateral root; Those nerves were surrounded by a common epineurium, however they were separable. The muscular branch to the biceps brachii muscle arose from the trunk ( fascicular bundle) dissected out from the median nerve and corresponding to the musculocutaneous nerve. Such variation may be of utmost clinical importance, especially during reconstructions of the brachial plexus or its branches.