Lining up tracks was no problem for railroad engineers. They did the same with tunnels all the time. The building of the Transcontinental had been turned into a race, and both companies did all they could to speed the work. Tunneling was very slow work. They would build a temporary track around the site of the planned tunnel, and work both ends of the tunnel at the same time. When they met, often the two ends of the tunnel were out of alignment by only a few inches. Consider that this included being accurate with the vertical alignment as well as horizontal. On the surface, only the horizontal alignment has to be considered. Sometimes they also dug to the middle, and worked outward, to advance the tunnel at 4 faces at once.

Another thing they did to speed the work was make the railroad bed far in advance of the end of the track. Surveyors lead the way, followed by the diggers miles behind, and finally, the track layers even more miles back. When the two lines neared one another, the most advanced crews of the rival companies kept working past their meeting point. They frequently crossed each other's rail beds.