This publication identifies and provides design guidelines for bridge scour and stream instability countermeasures that have been implemented by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selection, and design guidance are consolidated from other FHWA publications in this document to support a comprehensive analysis of scour and stream instability problems and provide a range of solutions to those problems. Selected innovative countermeasure concepts and guidance derived from practice outside the United States are introduced. Management...

This publication provides a comprehensive and practical guide for the design of stormwater pump station systems associated with transportation facilities. Guidance is provided for the planning and design of pump stations which collect, convey, and discharge stormwater flowing within and along the right-of-way of transportation systems. Methods and procedures are given for determining cumulative inflow, system storage needs, pump configuration and selection, discharge system size, and sump dimensions. Pump house features are identified and construction and maintenance considerations are...

Pressure flow (also known as vertical contraction) scour occurs when a bridge deck is insufficiently high such that the bridge superstructure becomes a barrier to the flow, causing the flow to vertically contract as it passes under the deck. A bridge deck is considered partially submerged when the lowest structural element of the bridge is in contact with the flowing water but the water is not sufficiently high to overtop the bridge deck. It is considered fully submerged when a portion of the flow overtops the bridge deck. Pressure flow generally only occurs in extreme flood events, but these...

Historically, culverts have been designed for hydraulic efficiency without consideration of fish passage or, more generally, aquatic organism passage. Over time, it has become apparent that culverts frequently become impediments to healthy aquatic ecosystems because they can prevent the movement of fish and other aquatic organisms upstream and downstream through the culvert. Therefore, aquatic organism passage through culverts has become an important design element component for road/stream crossings. Common physical characteristics that may create barriers include high water velocity,...

This manual presents a stream simulation design procedure, methods and best practices for designing culverts to facilitate aquatic organism passage (AOP). Although this manual focuses on culverts, the design team should recognize that an appropriate structure for any given crossing may be a bridge. This manual is not intended to conflict with or replace accepted guidance and procedures adopted in particular locations. When specific water crossing design methods are required in the jurisdiction where the crossing is located, those methods should be applied. In addition, local and regional...

Bridges are a vital component of the transportation network. Evaluating their stability and structural response after a flood event is critical to highway safety. Bridge studies are usually designed with an assumption of an open channel flow condition, but the flow regime can switch to pressure flow when the downstream edge of a bridge deck is partially or totally submerged during a large flood. Figure 1 shows a bridge undergoing partially submerged flow in Salt Creek, NE, in June 2008. Figure 2 shows a totally submerged flow in Cedar River, IA, in June 2008, which interrupted traffic on...

The Guide to Transportation Management Center (TMC) Data Capture for Performance and Mobility Measures is a two-volume document consisting of this summary Guidebook and a Reference Manual. These documents provide technical guidance and recommended practices regarding concepts, methods, techniques, and procedures for collecting, analyzing, and archiving TMC operations data to develop measures of roadway and TMC performance, as well as documenting the benefits of TMC activities for a variety of stakeholders. This guide is designed to be used by TMC technical and management staff involved in...

Storm drains generally collect storm runoff from streets, parking lots, and other structures and convey this water to a desired outfall. Access holes (or manholes), which allow staff to inspect, maintain, or repair a segment of the drainage, are usually spaced about 92 to 183 meters (m) (300 to 600 feet (ft)) apart along a given pipe and at every junction between multiple pipes. An access hole, which has at least one inlet pipe and one outlet pipe intersecting it, is usually constructed from a vertically oriented concrete pipe or box that is large enough for a person to enter by removing the...

Bottomless culverts are three-sided structures that use the natural channel for the bottom. These structures could be used to convey flows from one side of a highway to the other. As such, they are an environmentally attractive alternative to box, pipe, and pipe arch culvert designs. Bottomless culverts range in size from less than a meter (1.5 feet) to more than 10 meters (35 feet) in width. The failure of such a structure could have severe consequences similar to the failure of a bridge. On the other hand, since the cost of the foundation and scour countermeasures represents a significant...

Bottomless (or three-sided) culverts use the natural channel bed and are environmentally attractive alternatives to traditional closed culverts. Moreover, they are considered by many highway agencies to be economical alternatives for replacing short bridges. They are typically placed on spread footings, and the issue of scour and the depth of footing must be addressed. The scour problem is analogous to abutment and contraction scour in a bridge opening and can be treated in much the same manner. Since abutment scour estimates at bridge openings are often quite large, a scour protection task...