When the studies are realized to develop routes, streets, railroads, etc., both urban and rural they treat several disadvantages since they are the resistance of the soils, heights or levels, rain outlets etc., but one of the disadvantages that they emphasize is in the crossings.

 When it must develop in rural zone, the crossings are between streets of the same characteristics or importance, I access to cities or crossings of different characteristics since they are crossings with routes of the railroad and the surface mails.

When the studies are to develop in the urban zones, not only it is necessary to observe the characteristics of the ways, also observe the degree of urbanization. 

Because we emphasize in the topic of the crossings simply, because it is a way of seeing the risk of accidents, as increasing it or to avoid it completely.

If the traffic in different routes is big the crossings are of high risk, if the traffic in both routes is void the risk of accident is void, between these limits we must analyze that I choose type of crossing and that I place type of indication to inform that the crossing this one next.

1-The most common thing is to use crossings directly to level, this so much for routes of terrestrial transport or of these with railroads, I access to cities in case of rural zones and also used in streets of different priorities or importance in urban zones. As we were saying in the previous paragraph depending on the frequency of the traffic of both sense the risk will be therefore I must use the major quantity of signs already be visual, auditory etc. One of the variants to in this type of crossings is the rotunda, only usable in the cases of physical space to develop the rotunda and with terrestrial traffic, is not usable for the crossing railroad with terrestrial traffic.

When the crossings are to level we can never diminish the risk to zero always a situation will exist where the risk this one, already it is for negligence or because the devices of information stop working, but the crossings to level always generate accidents, even more if the crossing to level this one in urban zone. 

2-Crossings to difference, so much to realize crossings in highways, since in terrestrial transport with railroads, though it is mas costly we can say that the risks diminish practically to zero and the accidents are void. 

These crossings are used preferably in zones of high place I travel and in urban zones.

 Since conclusion we can say that the only way of avoiding the accidents on having realized a crossing way or with railroads it is to do steps to difference, it is not this way of seeing and comparing what happens with the beams, if we it can avoid in order that to look for it. 

ing. Roberto Rene Leal

La Plata 5 de Septiembre 2013