INFRASTRUCTURE Trackage The rail network is reasonably extensive. All major population centers are served and there are eight gateways linking FNM with U.S. railroads (Table 3). These gateways feed into three major north-south routings leading to the Valley of Mexico. Given the concentration of population in the Valley of Mexico, it is not surprising that rail lines are dense in that region relative to the rest of the nation. Overall, the trackage is in good to excellent condition. Both in terms of its condition and extent, trackage is not currently a limitation to growth. Indeed, if anything the system is underutilized. Along the three major north-south routes from the U.S. to the Valley of Mexico there are sufficient clearances for stack trains. However, this is not true for some other lines. FNM is developing plans for alleviating this situation. As part of this, CSX is loaning FNM a vehicle, which uses lasers for precisely measuring existing clearances. While the overall network is adequate, the absence of a rail corridor along the Gulf Coast is surprising. In particular, a direct rail link between Tampico and Veracruz would both promote economic growth along the coast and facilitate rail movements between the northern and western two thirds of the nation and the southeastern third of the nation without passing through Mexico City. Moreover, it should be noted that much of the trackage south of Mexico City has low weight limits, particularly in the Yucatan Peninsula.