The gases of exhaust of 25.173 vehicles that circulate in Bogotá were analyzed, between November of the 2002 and May of the 2003. Of the total of evaluated vehicles, 19.938 they consume gasoline and 5,233 vehicles operate to diesel engine. One was that the 14,7% of the vehicles to gasoline do not fulfill the limit allowed for carbon monoxide established by the environmental authority of the city and the 22,6% fail to fulfill the hydrocarbon standard. Also it was identified that the 30,8% of the vehicles to diesel engine display percentage of opacity of the smoke over the allowed limit. Of another part, one stands out that in the vehicles to gasoline that fail to fulfill the HC norm, the concentrations they exceed in more of twice the normative limit whereas in which they operate to diesel engine and that do not fulfill the opacity norm in average, the excedencia is near 45% of the allowed thing.