The former can occur as the flanges of the wheels are momentarily unsupported and unguided and can slip through the gaps in the rails, and the latter because the assembly contains elements that can break or vibrate loose.
Level junctions are considered a maintenance issue by railroad companies as the inherent gaps tend to be hard on locomotive and rolling stock wheelsets.
Level junctions are often found on tram or streetcar networks where lines cross or split.
While the latter crossing rarely causes delays, the former is at an intersection of four lines and cars often have to wait for others to pass at peak hours.
[3] In South Bay, San Diego at the South Bay Salt Works, as of 2001, survives the only crossing of narrow gauge track with standard gauge track, formerly utilized by the San Diego and Arizona Eastern Railway, in the United States.
In addition, the Sofia tramway has three diamond crossings between narrow and standard gauge tram tracks.