Prototype Information
For the vast majority of the American public a grade crossing is the only interface between a person and a railroad. Most everyone is familiar with them, in some facet, and usually the grade crossing sits empty. There may be more trains in operation, but the main lines do not cross urban America like they did in ages past.
In the prototype, grade crossing installations depend on the
history. If a road exists prior to the railroad being built, the
railroad has to both build and maintain the road crossing. But if a road is built after
the railroad is in place, the city or county has to build it and also
maintain it. The former case naturally results in great local
frustration, because the railroad rarely cares as much about a smooth
roadway as do the local citizenry, and it can be hard to get them to do
maintenance.
Types of Grade crossings. Grade crossing are of four basic types, and those types are designed and constructed based on the the type of road and the traffic it carries. Railroad Common Standards may name them differently but those types are (from low traffic to high traffic):
Type 1 crossings for farm and unimportant public road crossings where traffic is light.
Type 2 crossings for country roads and street crossings on which traffic is only moderately heavy.
Type 3 crossings for important streets in towns, main country roads and state highways which have heavy traffic.
Type 4 crossings for state and federal highways with heavy traffic.
The WWSL
The WWSL has a number of road grade crossings. The WWSL uses the road crossing type designations by traffic level identified above. Type 1 and Type 2 crossing are predominate and use a variety of filling materials between the rails. Specific engineering is consistent with the Union Pacific Common Standard.
Here is a copy of the Union Pacific Common Standards page for Grade Crossings dated 1928, with notes indicating updated standards to 1937.
The Union Pacific Common Standard reverses the type designations: Type 1 being high traffic and Type 4 being light traffic.
Three of the four types have different filling materials consistent with the era of the Common Standard: dirt, gravel, asphalt and concrete.
Later era filling material includes metal plates or grating, and rubberized mats.
Engineering. Some basic rules for grade crossing engineering are:
Road approaches should be level with the top of crossings for a distance of at least 20 feet outside the center line of track.. The road approach grade should conform to statutory requirements, but not more than one foot in sixteen feet.
When filling material (between the tracks) will not provide a hard smooth running surface, it should be topped with suitable material of adequate thickness to withstand the wear and maintain an even surface.
Rail joints should be arranged that they will fall outside of crossings wherever practical.
Road Construction Technique
Road Construction techniques are not covered by the 4.1.12 series. See 5.9.1 Dirt Road, 5.9.2 Gravel Road, 5.9.3 Asphalt Road, and 5.9.4 Concrete Road for the appropriate road construction technique.
Grade Crossing Construction Techniques.
Type 1 - Unimproved grade crossing - dirt, rock or gravel. See 4.1.12.1 for construction details.
Type 2 - Rural road crossing (Light Traffic)- plank along rail to form box, with dirt, gravel, or rock. See 4.1.12.2 for construction details.
Type 3 - Rural road crossing (Medium Traffic) - wood plank, rail, or asphalt. See 4.1.12.3 for construction details.
Type 4 - Heavy Traffic crossing - metal, concrete or rubber panel. See 4.1.12.4 for construction details.
Reference
Union Pacific Common Standard, Road Crossing
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