In the past, there were several bridges that were constructed but collapse shortly due to its engineering design. One of the bridges that severe was the Tacoma Narrow Bridge in 1940 November 7. Even though no one was killed in the collapse, the damage and cost it has done was way more than anyone had expected. Hence, from then on, engineers must calculate exactly to prevent such cases from happening in the future. Or else, you may never know when will someone die because of an inaccurate calculation.
Hence, our engineering goal is to design a bridge which will be able to sustain the structural efficiency (E) of more than 200. This will mean that most of the vehicles (like trucks and cars) are able to cross the bridge safely.
Our requirements would be to have a length of a bridge that is between 550mm to 650mm, maximum width of 120mm and maximum height of 200mm. The maximum weight will be 500g.