I was asked to design a county bridge in my state. Counties typically use high abutment bridges to minimize the overall length of the bridge. if the bridge is under 40′ then they use non-prestressed precast deck panels.
The biggest benefit is the cost. A typical 40′ long by 28′ wide bridge costs just over $100,000. The bridge I designed has 2:1 berm slopes and is the DOT favorite spill-through abutment bridge. The advantages of the spill-through bridge are working in the dry, wider stream opening and because it is the most commonly built bridge, it has access to a lot of standard parts.
The biggest drawback is that it costs more and counties are strapped for cash. My ABC design should be built in 5 days but the cost will be closer to $200,000. Yikes!