Free download AASHTO Pedestrian Bridge Specifications pdf

Reference may be made to the Texas Transportation Institute Research Study , Safe End Treatment for Roadside Culverts 13 , in which researchers concluded that a passenger vehicle should be able to traverse a pipelslope combination at speeds up to 80 k m h [50 mph] without rollover. To achieve this result, the roadway or ditch foreslope and the driveway foreslope both should be 1V:6H or flatter and have a smooth transition between them.

Ideally, the culvert should be cut to match the driveway slope and fitted with cross members perpendicular to the direction of traffic flow as described previously. This study suggests that it could be cost-effective to flatten the approach slopes to 1V6H and match the pipe openings to these slopes for all sizes of pipes up to mm [36 in. The addition of grated inlets to these pipes was considered cost-effective for pipes mm [36 in.

Because these numbers were based in part on assumptions by the researchers, they should be interpreted as approxi- mations and not as absolute numbers. Figure illustrates a possible design for the inlet and outlet end of a parallel culvert. When channel grades permit, the inlet end may use a drop-inlet type design to reduce the length of grate required. A mm [ in. The recommended grate design may affect culvert capacity if significant blockage by debris is likely; however, because capacity is not normally the governing design criteria for parallel structures, hydraulic efficiency may not be an overriding concern.

A report issued by the University of Kansas suggests that a 25 percent debris blockage factor should be sufficiently conservative to use as a basis for culvert design in these cases 8.

This report also suggests that under some flow conditions, the capacity of a grated culvert may be. In those locations where headwater depth is critical, a larger pipe should be used or the parallel drainage structure may be positioned outside the clear zone, as discussed in the following section. Some parallel drainage structures can be moved laterally farther from the through traveled way. This treatment often affords the designer the opportunity to flatten the transverse slope within the selected clear-zone distance of the roadway under design.

If the embankment at the new culvert locations is traversable and likely to be encroached upon by traffic from either the main road or side road, safety treatment should be considered. It is suggested that the inlet or outlet match the transverse slope regardless of whether additional safety treatment is deemed necessary. Figure 1 shows a suggested design treatment, while Figure shows a recom- mended safety treatment for parallel drainage pipes. Flow in Drainage Channel.

In cases in which the transverse slope cannot be made traversable, the structure is too large to be safety treated effectively, and reloca- tion is not feasible, shielding the obstacle with a traffic barrier may be necessary. Specific information on the selection, location, and design of an appropriate barrier system is in Chapter 5. Drop inlets can be classified as on-roadway or off-roadway structures. On-roadway inlets are usually located on or alongside the shoulder of a street or highway and are designed to intercept runoff from the road surface.

These include curb opening inlets, grated in- lets, slotted drain inlets, or combinations of these three basic designs. Because they are installed flush with the pavement surface, they do not constitute a significant safety problem to errant motorists. However, they should be selected and sized to accommodate design water runoff. In addition, they should be capable of supporting vehicle wheel loads and should be pedestrian and bicycle compatible. Off-roadway drop inlets are used in medians of divided roadways and sometimes in roadside ditches.

Although their purpose is to col- lect runoff, they should be designed and located to present a minimal obstacle to errant motorists. This goal can be accomplished by building these features flush with the channel bottom or slope on which they are located.

No portion of the drop inlet should project more than mm [4 in. The opening should be treated to prevent a vehicle wheel from dropping into it; however, unless pedestrians are a consideration, grates with openings as small as those used for pavement drainage are not necessary.

Neither is it necessary to design for a smooth ride over the inlet; it is sufficient to prevent wheel snagging and the resultant sudden deceleration or loss of control. Discussion-The available recovery area of 8. If the culvert headwall is greater than mm [4 in. If the foreslope contains rough outcroppings or boulders and the headwall does not significantly increase the obstruction to a motorist, the decision to do nothing may be appropriate.

A review of the highway's crash history, if available, may be made to determine the nature and extent of vehicle encroachments and to identify any specific locations that may require special treatment. Discussion-The available recovery area of 1. If this section of road has a significant number of run-off-the-road crashes, it may be appropriate to consider shielding or removing the entire row of trees within the crash area.

If this section of road has no significant history of crashes and is heavily forested with most of the other trees only slightly farther from the road, this tree would probably not require treatment. If, however, none of the other trees are closer to the roadway than, for example, 4. If a tree were 3. This example emphasizes that the clear-zone distance is an approximate number at best and that individual objects should be analyzed in relation to other nearby obstacles.

Discussion-Since the non-recoverable foreslope is within the recommended suggested clear-zone distance of the 1VH foreslope, a runout area beyond the toe of the non-recoverable foreslope is desirable. Using the steepest recoverable foreslope before or after the non-recoverable foreslope, a clear-zone distance is selected from Table In this example, the 1V:SH foreslope beyond the base of the fill dictates a 9 to 10 m [30 to 32 ft] clear-zone distance.

Since 7 m [23 ft] are available at the top, an additional 2 to 3 m [7 to 10 ft] could be provided at the bottom. Since this is less than the 3 m [lo ft] recovery area that should be provided at the toe of all the non-recoverable slopes the 3 m [lo ft] should be applied.

All foreslope breaks may be rounded and no fixed objects would normally be built within the upper or lower portions of the clear-zone or on the intervening foreslope. Discussion-Since the critical foreslope is within the suggested clear-zone distance of 9 to However, if this is an isolated obstacle and the roadway has no significant crash history, it may be appropriate to do little more than delineate the drop-off in lieu of foreslope flattening or shielding. Discussion-The available recovery area of ;I is 0.

If much of this roadway has a similar cross section and no significant run-off-the-road crash history, neither foreslope flattening nor a traffic barrier would be recommended. On the other hand, even if the 1V5H foreslope were 3 m [lo ft] wide and the clear-zone re- quirement were met, a traffic barrier might be appropriate if this location has noticeably less recovery area than the rest of the roadway and the embankment was unusually high. Discussion-Since the range for the flatter slope of 26 to 30 ft extends past the slope break onto the steeper slope, the upper end of this range should be considered.

However, the range for the steeper slope of 32' to 40' might be considered conservative since the majority of the clear zone area is on the flatter slope. Thus the lower range of this slope might be considered. An appropriate range for this combination slope could be 30 to 32 ft.

In this example, it would be desirable to have no fixed objects constructed on any part of the 1V5H foreslope. Natural obstacles such as trees or boulders at the toe of the slope would not be shielded or removed.

However, if the final foreslope were steeper than 1V4H, a clear runout area of 3 m [lo ft] should be considered at the toe of the foreslope. The designer may choose to limit the clear-zone distance to 9 m [30 ft] if that distance is consistent with the rest of the roadway template, a crash analysis or site investigation does not indicate a potential run-off-the-road problem in this area, and the distance selected does not end at the toe of the non-recoverable foreslope.

Discussion-For channels within the preferred cross-section area of Figures or , the clear-zone may be determined from Table 3- 1. However, when the suggested clear-zone exceeds the available recovery area for the foreslope, the backslope may be considered as additional available recovery area. The range for the suggested clear zone for the foreslope of 6 to 7. Since the backslope cut has a suggested clear-zone of 5 to 5.

In addition, fixed objects should not be located near the center of the channel where the vehicle is likely to funnel. An appropriate range for this combination slope could be 20 to 24 R. Because the tree is located beyond the suggested clear zone, removal is not required. Removal should be considered if this one ob- stacle is the only fixed object this close to the through traveled way along a significant length.

Drainage channels not having the preferred cross section see Figure or should be located at or beyond the suggested clear zone. However, backslopes steeper than 1V:3H are typically located closer to the roadway. If these slopes are relatively smooth and unobstructed, they present little safety problem to an errant motorist.

If the backslope consists of a rough rock cut or outcropping, shielding may be warranted as discussed in Chapter 5. Discussion-The ditch is not within the preferred cross section area of Figure and is 0.

However, if the ditch bottom and backslope are free of obstacles, no additional improvement is suggested. A similar cross section on the outside of a curve where encroachments are more likely and the angle of impact is sharper would probably be flattened if practical.

Discussion-The rock cut is within the given suggested clear-zone distance but would probably not warrant removal or shielding unless the potential for snagging, pocketing, or overturning a vehicle is high.

Steep backslopes are clearly visible to motorists during the day, thus lessening the risk of encroachments. Roadside delineation of sharper than average curves through cut sections can be an effective countermeasure at locations having a significant crash history or potential. Highway Clear Zone. Highway Clear Zone f 4- Cross Section. The suggested clear zone should be the greater of the two clear zones. Refer to the bold line in the above figure for the overall suggested clear zone.

Refer to Examples K and L for the ramp clear zones. I Shoulder. Discussion-Refer to the bold line in the above figure for the overall suggested clear zone. As an alternative, the clear zones for ramp may be set at 9 m [30 ft] if previous experience with similar projects or designs indicates satisfactory experience. See Example-J for the speed-change lane clear zones. Shoulder I Ramp Shoulder. Radius: m [1, ft] Suggested clear-zone distance for 4: 1 foreslopes along the inside of curve: 2.

Radius: m [1, ft] Suggested clear-zone distance for 6:l foreslopes along the inside of curve: 3. Acceleration Lane Clear Zone. See Example J for the speed-change lane clear zones.

Highway Safety Design and Operations Guide. To be released Fall 20 Graham, J. Highway Engineering Series No. McEnroe, B. KU- University of Kansas, Lawrence, KS, Olson, R. Weaver, H. Ross, and E. Jackson, and D. Sicking, T. Hirsch, H. Cooner, J. Nixon, S. Fox, and C. Safety Treatment ofRoadside Drainage Structures.

Transportation Research Record Bielenberg, J. Rohde, J. Reid, R. Faller, and K. Safety Gratesfor Cross-Drainage Culverts. Weaver, G.

Marquis, and R. Although a traversable and unobstructed roadside is highly desirable from a safety standpoint, some appurtenances simply should be placed near the traveled way. Man-made fixed objects that frequently occupy highway rights-of-way include highway signs, roadway lighting, traffic signals, railroad warning devices, intelligent transportation systems ITS , mailboxes, and utility poles. According to the Insurance Institute for Highway Safety IIHS 7 , since the proportion of vehicle deaths involving collisions with fixed objects has fluctuated between 19 and 22 percent see Section 1.

Approximately 50 percent 4, of all fixed-object fatalities involve crashes with trees, 5 percent involve sign and lighting supports, and 12 percent 1, involve utility poles. Although they are less frequent, collisions with other roadside hardware are frequently severe as well. Figure shows the percent distribution of fixed-object crash deaths in by object struck. This chapter is not intended to provide technical design details.

Similarly, information on existing operational hardware is included only to the extent necessary to familiarize the designer with the types of breakaway devices available and how each is intended to function.

The highway designer is charged with providing the safest facility practicable within given constraints. As noted in Chapter 1, there are six options for mitigation of objects within the design clear zone: 1. Remove the obstacle 2. Redesign the obstacle so it can be traversed safely 3. Relocate the obstacle to a point where it is less likely to be struck 4. Reduce impact severity by using an appropriate breakaway device 5.

Shield the obstacle with a longitudinal traffic barrier designed for redirection or use a crash cushion or both if it cannot be elimi- nated, relocated, or redesigned 6. Delineate the obstacle if the above alternatives are not appropriate While the first two options are the preferred choices, these solutions are not always practical, especially for highway signing and light- ing, which should remain near the roadway to serve their intended functions.

This chapter deals primarily with the fourth option: the use of breakaway hardware, which has become a cornerstone of the forgiving roadside concept since its inception in the mids.

Emphasis is placed on the selection of the most appropriate device to use in a given location and on installing the support needed to ensure acceptable performance when the device is hit. The final section of this chapter addresses the problems associated with trees and shrubs and provides the designer with some guidelines to follow on this frequently sensitive topic.

The term breakaway support refers to all types of sign, luminaire, and traffic signal supports that are designed to yield, fracture, or separate when impacted by a vehicle. The release mechanism may be a slip plane, plastic hinge, fracture element, or a combination of them. Newly developed supports tested under MASH will un- dergo an additional crash test with a pickup truck; this test is intended to evaluate potential for windshield penetration with a taller pas- senger vehicle than has been used for testing in the past.

NCHRP Report and MASH criteria require that a breakaway support perform in a predictable manner when struck head-on by an kg [ lb] andlor kg [ Ib] vehicle, or its equivalent, at speed from 30 kmih [19 mph] to kmlh [62 mph].

Limits are placed on the transverse and longitudinal components of the occupant impact velocity and the crash vehicle should remain stable and upright during and after the impact with no significant deformation or intrusion of the windshield or passenger compartment.

These specifications also establish a maximum stub height of mm [4 in. The appropriate procedures for acceptance testing of breakaway supports are described in Sections 2.

Full-scale crash tests, bogie tests, and pendulum tests are used in the acceptance testing of breakaway devices. In full-scale testing, an actual vehicle is accelerated to the test speed and impacted into the device being tested. The point of initial impact is the front of the vehicle, either at the center or quarter point of the bumper.

Full-scale tests produce the most accurate results, but their main disadvan- tage is cost. Bogie vehicles also are used to test breakaway hardware. A bogie is a reusable, adjustable surrogate vehicle used to model actual vehicles. A nose, similar to a pendulum nose, is used to duplicate the crush characteristics of the vehicle being modeled.

To reduce testing costs, pendulum tests are used to evaluate breakaway hardware. Pendulum nose sections have been developed that model the fronts of vehicles. Pendulum tests typically have been used to test luminaire support hardware. This extrapolation method should not be used with base-bending or yielding supports.

Sign, luminaire, traffic signal, and similar supports first should be structurally adequate to support the device mounted on them and to resist ice, wind, and fatigue loads as specified in the AASHTO Standard SpeciJicationsfor Structural Supports for Highway Signs, Luminaires and Trafic Signals 3. Other concerns are that supports be properly designed and carefully located to ensure that the breakaway devices perform properly and to minimize the likelihood of impacts by errant vehicles.

For example, supports should not be placed in drainage ditches where erosion and freezing could affect the proper operation of the breakaway mechanism. Building a footbridge.

Non-Curb Section 1. Support beam materials other than steel include engineered beams like LVL or Glulam, wood, and concrete. The blocks were cut into individual pieces on site and assembled into a prestressed arch. To allow for the various uses, the building was designed with only four interior columns from the ground floor up.

Robert Benson Photography A footbridge leads to an entrance of the 20 - 2x10 1. Free Shipping. Call Us: But what really rules is that rail-less footbridge. Typical Abutment. Conductor Arthur Fiedler, who led the Pops from to , spearheaded the campaign to bring music to the Esplanade. StonemontQC is fully integrated with the aggregate portion allowing for mix component properties to be easily kept current with data from aggregate plants. Bike shares, a barge pool and a bridge connecting the east and west sides of the Inner Harbor are just a few ideas wrapped Design, Supply and Installation of a 2.

If you require extra capacity for your foot bridge, please reach out. First - explore, discover, be inspired at our shop and get your project going. This is a set of design criteria developed for highway bridges.

How the design wizard works. Springboard Centre. Build a graceful footbridge - Article by Harrison Stone from Issue The entire cost for Lumber, concrete, and fasteners was around 0. Construction of the superstructure was comprised of a This We offer all kinds of bridges — from Burma style V-bridges to suspension bridges with walkways of wood or synthetic lumber.

Wooden bridges are invariably a more economic solution than any other. We design for uniform live loads, snow loads, vehicle loads, wind loads, and seismic loads. Free garden bridge plans. Resources for building John R. Since revisions or additions to the design file drawings may occur at any time, the Receiver agrees to indemnify, defend and hold harmless WSDOT, its officers, agents, and employees from and against any and all claims, suits, losses, damages or costs, including reasonable attorney's fees, arising from the use of outdated design file drawings NOTE: Removal of a box girder structure costs from - per square foot.

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The primary function of the Bridge Design Section is to provide the necessary program management, project management, engineering and plan preparation expertise for various types of fixed and movable bridges. ES VARI 25 FLATS 0 ANGLE FLAT 2. FLAT M. Gratings and frames are to be galvanised by hot-dip galvanising process in 7.

All weld to be full strength butt weld unless otherwise stated. Drop-inlet chamber shall not be installed within the width of walkway. The complete assembly except fish tail are to be galvanised by hot-dip galvanising 9. Fish tail is to be welded to M. Gradation for 20mm graded stones: 2. All upvc pipe shall conform to SS Precast concrete sump for sub-soil drain shall be provided at 60m interval.

B SEP jointing minimum wall thickness 9. Shorter length of mm or mm precast concrete kerbs shall be used on sharp radius.

W HI TE. Kerbs are to be painted with one coat of approved gloss enamel paint in alternate black and white colour. NG 70m EL. For definition of civic district, refer to URA's website for details. For kerb at curve and corner of radius less than 15m, the precast kerb shall be formed at curve of the same radius.

Gratings and frames are to be shop fabricated. All M. The M. OT RG Gradient of ramps shown in the details shall not be exceeded. The ramps shall be broom brushed. Details to be used when footpath is next to the kerbs. Yellow coloured tactile tiles shall be provided on the concrete footpath ramp.

No obstruction shall be placed within the pedestrian crossing zone. A OCT No drop-inlet chamber shall be placed within the pedestrian crossing zone. VE NI 1m. B SIN O. Drop-inlet chamber and scupper pipe is to be provided only where there is a provision of a drain at the traffic island. Clear zone shall be free of obstruction. Railings are to be provided next to open drain. Concrete cover shall be of 45mm.

MI B MIN 1m. ISE NOTES: 4. Vehicular Travel Lane. Turns are made using the outside turning radius for the complete truck. The design tandem, representing two trailers in series attached to one truck, consists of a pair of Four cylinder overhead valve, liquid cooled, hydraulic lifters. April 25th, - How to Calculate the Turning Radius of a Truck With With a 10 degree angle of truck to trailer the turning radius is a rigger at a fire engine factory and' '9 21 4 14 2 GVW 41 69 20 6 This surface is the rearmost point of driver's seat on trucks with closed cargo area and is the front surface of the inside of cargo box on trucks with open cargo area.

A few simple steps to open a vehicle 1. The angle of approach should be no more than 16 degrees. Powerful and efficient. Width of the tire tread.

Turning Radius Guidelines for Trucks. Watch for marked areas. The City of Columbus, Department of Public Service, Division of Design and Construction maintains standard construction drawings related to transportation facilities and work performed in the City's right-of-way. WB is the wheelbase distance between centers of the front and back wheels This formula assumes a perfect theoretical turning scenario. If anyone has this that they can share, I'd really appreciate it.

The shorter the wheelbase, the tighter the turning radius. Truck turning radius All areas designed for vehicular traffic will need to be accessed by the ladder truck. The LMTV was designed as a 4x4 with a 2. In doing so, DPW has received and performed research related to the existing AlertOC is a mass notification system designed to keep Orange County, California residents and businesses informed of emergencies that may require immediate life saving actions.

If you don't want the truck to encroach on the oncoming lane, you'll need a large corner radius, or one of the alternates in the Green Book like a three-centered curve or curve with tapers. Non-Truck Turns Intersection corners with no large truck right turn s or all day large truck turning restrictions shall be assumed to be non-truck turn types. Water and fuel trucks, and crummy parking. In addition, trucks and other large vehicles can affect safety and operations by off-tracking into adjacent lanes or the shoulder.

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