Roadway Infrastructure for Autonomous Vehicles

This application is a continuation of U.S. Patent Application No. U.S. patent application Ser. No. 18/395,188, filed Dec. 22, 2023, and titled “Roadway Infrastructure for Autonomous Vehicles” which is a continuation of U.S. patent application Ser. No. 17/541,106, filed Dec. 2, 2021, and titled “Roadway Infrastructure for Autonomous Vehicles,” now U.S. Pat. No. 11,885,076, which is a division of U.S. patent application Ser. No. 16/930,164, filed Jul. 15, 2020, and titled “Roadway Infrastructure for Autonomous Vehicles,” now U.S. Pat. No. 11,346,060, which is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 62/874,875, filed Jul. 16, 2019 and titled “Roadway Infrastructure for Autonomous Vehicles,” the disclosure of which is hereby incorporated herein by reference in its entirety.

The described embodiments relate generally to roads for vehicles, and, more particularly, to separated grade (elevated) roadways for autonomous vehicles.

Vehicles, such as cars, trucks, vans, busses, trams, and the like, are ubiquitous in modern society. Cars, trucks, and vans are frequently used for personal transportation to transport relatively small numbers of passengers, while busses, trams, and other large vehicles are frequently used for public transportation. Vehicles may also be used for package transport or other purposes. Such vehicles may be driven on roads, which may include surface roads, bridges, highways, overpasses, or other types of vehicle rights-of-way.

An elevated roadway for autonomous vehicles may include a pylon extending vertically from a ground anchor and comprising a metal tube defining a central cavity and a concrete column within the central cavity. The elevated roadway may further include a bracket coupled to the pylon and comprising a mounting plate secured to the pylon and a cantilevered road support member extending from the mounting plate. The elevated roadway may further include a cantilevered road section coupled to the pylon via the cantilevered road support member and comprising a joist structure structurally coupled to the cantilevered road support member, a road member above the joist structure and supported by the joist structure, and first and second side barriers along first and second sides of the road member, respectively. The road member may be adapted to receive a four-wheeled roadway vehicle. The mounting plate may be secured to the pylon via anchors embedded in the concrete column.

The concrete column may include steel-reinforced concrete. Either the metal tube or the concrete column may be capable of fully supporting a weight of the cantilevered road section. The joist structure may include a plurality of parallel joists. The plurality of parallel joists may include four parallel joists. The cantilevered road section may further include a metal form coupled to the joist structure and a concrete road support formed in the metal form, and the road member and the concrete road support may be parts of a monolithic structure.

A road section for an elevated roadway for autonomous vehicles may include a joist structure comprising a plurality of parallel joists, a metal form coupled to the joist structure, and a monolithic road structure including a road member and a plurality of road supports formed in the metal form and configured to transfer load from the road member to the joist structure. The joist structure may include four joists arranged in parallel. The joist structure may further include a plurality of inter-joist support members.

The joist structure may have a length of fifty feet or less. The joist structure may have a length of 33 feet or less. The road section may further include a water conduit extending substantially parallel to the plurality of parallel joists and configured to carry water from the road member to a water outlet. The joist structure may define a horizontal top plane and the plurality of road supports may have different heights to support the road member in a non-parallel orientation relative to the horizontal top plane.

The joist structure may be configured to be coupled to one or more additional joist structures to define a joist span, and the joist span may be configured to be supported by a first pylon at a first end of the joist span and a second pylon at a second end of the joist span. The joist span may have a length of 100 feet, and may be formed of two 50 foot joist structures, three 33 foot joist structures, or any other suitable combination of joist structures.

An elevated roadway for autonomous vehicles may include a plurality of pylons, each respective pylon of the plurality of pylons extending vertically from a respective ground anchor, and a cantilevered roadway supported by the plurality of pylons and defining, along at least a portion of the cantilevered roadway, a first side extending parallel to a direction of vehicular travel and a second side extending parallel to the direction of vehicular travel. Each pylon of the plurality of pylons may be positioned along the first side of the portion of the cantilevered roadway. The cantilevered roadway may be a first cantilevered roadway and the elevated roadway may further include a second cantilevered roadway supported by the plurality of pylons and positioned vertically above the first cantilevered roadway. The pylons may be set apart from one another by 100 feet or less. The cantilevered roadway may include a plurality of road sections joined end-to-end.

A pylon for an elevated roadway may include a metal tube defining a central cavity, a concrete column within the central cavity, and a first conduit at least partially embedded in the concrete column and defining an inlet proximate a top of the pylon and configured to receive water and an outlet proximate a bottom of the pylon and configured to eject water from the first conduit. The pylon may further include a second conduit at least partially embedded in the concrete column and configured to house a wire, the second conduit defining a first opening proximate the top of the pylon and a second opening proximate the bottom of the pylon. The pylon may be configured to support an elevated roadway.

The metal tube and the concrete column may define fully redundant load paths for supporting the elevated roadway. The concrete column may be reinforced with steel reinforcing members. The pylon may further include a reinforcement sleeve extending around a base portion of the metal tube. The pylon may further include a water reservoir within the reinforcement sleeve, and the outlet of the first conduit may be configured to eject water from the first conduit into the water reservoir.

Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.

The embodiments herein are generally directed to a transportation system in which numerous vehicles may be autonomously operated to transport passengers and/or freight along a roadway that includes elevated roadway segments. For example, a transportation system or service may provide a fleet of vehicles that operate along a roadway to pick up and drop off passengers at either pre-set locations or stops, or at dynamically selected locations (e.g., selected by a person via a smartphone). In some cases, it may be necessary or otherwise beneficial to elevate all or some of the roadway that the vehicles traverse. For example, in dense, urban environments, it may not be practical or desirable to devote existing traffic lanes or sidewalks to dedicated autonomous vehicle lanes. Accordingly, described herein are systems for elevating a roadway above ground level so that autonomous vehicle roadways may be provided while reducing or minimizing the impact on existing roads, sidewalks, and other infrastructure. As used herein, the term “roadway” may refer to a structure that supports moving vehicles.

Separated grade roadways (also referred to herein as elevated roadways) for autonomous vehicles may include a series of pylons that are anchored into the ground and support the roadway. The roadway may be formed of multiple modular (and optionally at least partially prefabricated) road sections that are coupled to the pylons. Notably, the elevated roadways described herein may not be accessible to conventional roadway vehicles (e.g., cars, trucks, vans). Further, the vehicles that are used with the elevated roadways may be centrally controlled or otherwise programmed to operate according to a particular set of rules. Accordingly, the maximum loading of the elevated roadways may be a known or at least highly controllable quantity. By contrast, conventional roadways and bridges must be designed to accommodate an unknown worst-case loading scenario that includes vehicles of different sizes, weights, speeds, and the like. Because the loading of the elevated roadways of the transportation system described herein can be highly controlled, and also because the vehicles of the transportation system are relatively small and light compared to conventional road-going vehicles, the elevated roadways described herein may be smaller and lighter than a conventional bridge or highway span.

As noted above, the elevated roadway may include a series of modular roadway sections that are supported above the ground by a series of pylons. The roadway sections may include a joist structure that can be at least partially manufactured remotely (e.g., prefabricated) and shipped to an installation site, where it may be coupled with other joist structures and ultimately raised and coupled to the pylons. The joist structures may be formed of multiple individual joists that may be sized so they can be shipped using conventional shipping methods. For example, the joists may be configured to fit in land-sea-air containers, on flatbed semi-trucks, or the like. In some cases, multiple joists may be fitted into a single land-sea-air container or on a trailer of a semi-truck. The multiple joists may then be coupled together to form a joist structure, which may then be combined (e.g., end-to-end) with other joist structures and then coupled to the pylons. Because of the modular, pre-manufactured nature of the joists, as well as their ability to be transported using conventional shipping methods such as land-sea-air containers and semi-trucks, deployment of the elevated roadway may be faster and more efficient than conventional road construction methods.

Once elevated and coupled to the pylons, concrete road structures may be built on top of the joist structures to define the actual wearing surface of the roadway (e.g., the surface that the vehicle tires contact). The road structures may be built on top of the joist structures by attaching forms (e.g., molds that define the shape of the road structure) to the joists, and filling the forms with a concrete deposition machine. Notably, the road structures need not be simple flat, planar slabs that sit atop the joist structures. Rather, the road structures may define curves, banks, inclines, declines, or other shapes in addition to basic flat slabs. In this way, though the road structures may all be monolithic concrete structures, they may have unique shapes that cooperate to define the straights, curves, hills, and banks of the road structures. Additional details about the road structures and techniques for forming them are described herein.

As noted above, the roadway may be part of a transportation system that includes or operates with a dedicated type of vehicle (or several dedicated types of vehicles), which may be configured to independently operate according to known rule sets or control schemes, and which may also be subject to being directly controlled or guided by a supervisory control system. As used herein, “vehicle control schemes” may refer to control schemes that are executed by an individual vehicle (also referred to as “local control schemes”), as well as central and/or distributed control schemes that may have the ability to control multiple different vehicles (which are also referred to as “supervisory control schemes”). It will be understood that vehicle control schemes may include elements of both local and supervisory control schemes to control the vehicles such that there may not be (and need not be) a clear or well-defined functional or programmatic boundary between the local and supervisory control schemes.

Because the transportation system and its vehicles are typically limited to autonomous vehicles (e.g., there are typically no human drivers independently piloting the vehicles), and more particularly to known types of vehicles, the shape and contour of the road structures may be designed in concert with the vehicles and the vehicle control schemes. For example, because the specifications of the vehicles are known (e.g., maximum speed, turning radius, maximum braking performance, acceleration capabilities, etc.), the roadway may be designed in concert with the vehicle specifications to produce a target ride characteristic and to achieve an overall vehicle and roadway performance.

Further, autonomously controlling vehicles using the vehicle and supervisory control schemes allows a greater range of roadway shapes and contours to be used. For example, while it may be necessary to avoid building small-radius turns in a conventional highway (because it would be unsafe to require human drivers to make drastic speed and direction changes), such turns may be feasible in the instant system. In particular, because the entire roadway is known to the transportation system, all of the vehicles on the roadway may be specifically configured to make appropriate speed adjustments and steering movements to safely and comfortably navigate the roadway, even if there are sharp turns, banked turns, inclines, declines, or the like that would otherwise be too dangerous or inconvenient on conventional roadways.

In some cases, the transportation system may be designed to result in a particular ride characteristic for occupants when the vehicles are traversing the roadway. As used herein, “ride characteristic” may refer to a set of physical parameters (such as forces or accelerations) that are experienced by an occupant of a vehicle traversing along the roadway. In some cases, the ride characteristic may be characterized by a set of target values or upper limits or thresholds (e.g., on lateral and vertical acceleration) that will be experienced by an occupant while travelling over the roadway in a vehicle (e.g., the system may be configured to maintain the acceleration forces experienced by vehicle occupants at or below threshold levels). As one specific example, the accelerations felt by a user may be limited in fore, aft, and lateral directions to less than 0.5 times the force of gravity (g), while vertical acceleration may be maintained between 0.5 g and 1.5 g. (These acceleration limits may be established for a location within the vehicle where a passenger's head would be during normal vehicular travel.) Other kinematic properties may also be subject to targets, upper limits, or thresholds. For example, in addition to or instead of acceleration, the transportation system, and in particular the shape of the roadway, may be designed so that velocity, jerk, and snap may all be maintained at or near target values, or at or below limits or threshold values. Further, to provide a consistent experience, these targets and/or limits may be applied along the entire or substantially the entire roadway. By designing the roadway (e.g., the turns, inclines, declines, banks, camber, etc., of the roadway) to achieve a target ride characteristic, passengers may experience the sensation of gliding, without the abrupt and varying lateral, fore/aft, and vertical acceleration changes that occur when travelling along a conventional road.

The foregoing threshold values for acceleration are merely exemplary values, and other values or ways of quantifying the target ride characteristics are also contemplated. Notably, as described above, these ride characteristics may be maintained even along roadways that include highly-banked turns, steep inclines or declines, small-radius turns, and the like. For example, the vehicles may be programmed to traverse these roadway features in a way that maintains the desired ride characteristics. Indeed, as described herein, the vehicles may include features such as four-wheel steering and four-wheel independently adjustable suspension (including adjustable ride heights, preloads, damping, etc.) that may be used to help maintain the target ride characteristics along various types of roadway features, shapes, and configurations.

illustrates a section of an example elevated roadwayfor autonomous vehicles, in accordance with embodiments described herein. The section of elevated roadway that is shown inis alongside and/or above a conventional surface road, illustrating the elevated roadway deployed in a typical urban or suburban environment, though this is not meant to be limiting. Indeed, the elevated roadway may be deployed in any environment or location, including rural locations, entirely or partially inside buildings, away from roadways, underground, or the like. The elevated roadwayis shown supporting a plurality of four-wheeled vehicles. The vehiclesmay be autonomous or semi-autonomous vehicles specifically designed for use with the elevated roadway. One example type of vehicle for use with the elevated roadwayis described with respect to, though other types of vehicles may be driven along the elevated roadwayinstead of or in addition to those described herein.

The elevated roadway is supported by a plurality of pylonsthat extend vertically from a ground anchor; in some embodiments, each section of the elevated roadwaymay be affixed to its own pylon, while in other embodiments each section of the elevated roadwaymay be affixed to multiple pylons. The pylonsmay be spaced apart by any suitable distance. In some cases, the pylonsare spaced apart by about 100 feet (thus defining roadway spans of about 100 feet). The spacing of the pylonsmay be defined by or consistent with the dimensions of standardized-length road sections that are used to form the elevated roadway. For example, road sections may have a standardized length of about 33 feet to allow the sections (or at least the joists of the road sections) to be at least partially prefabricated (remotely) and shipped to the build site in land-sea-air containers, or about 50 feet to allow them to be shipped by semi-trucks. Accordingly, the 100-foot distance between joists allows the roadway spans to be formed of either three 33-foot road sections or two 50-foot road sections. The standardization of the pylon spacing and joist length simplifies design and construction logistics, as the pylon spacing can be standardized even across regions with different shipping constraints.

The distance between pylonsmay be generally uniform along the length of an elevated roadway. For example, all or most of the pylonsmay be spaced about 100 feet apart from one another. The uniform spacing may help simplify the design and construction of the elevated roadway. Nevertheless, in some cases it may be necessary or beneficial to have a different spacing between pylons, such as where the roadway curves or turns, or to accommodate buildings, obstacles, or other features along the path of the elevated roadway. In some cases, where the distance between pylons is other than 100 feet, the distance may be 33 feet or 50 feet (or any additive combination of these distances) so that the standardized road sections can be used. In other cases, customized road sections having other lengths may be provided to accommodate any suitable distance between pylons.

Each pylonmay include a bracketthat is secured to the pylonand supports one or more cantilevered road sections. The elevated, cantilevered arrangement of the road sectionsmay provide several advantages over other types of elevated bridges or highway spans. For example, because the road sectionsneed only be supported along one side, the pylonsmay be positioned along whichever side of the road sectionsis most advantageous based on construction constraints, space considerations, or the like. Further, because the road sectionsare cantilevered from the pylons, the entire width of the road sectionsmay define an unobstructed covered path that can be used for covered sidewalks, roads, and the like. By contrast, roadways that are directly on top of their pylons (e.g., centered over the pylons), the path defined beneath the roadway is inconveniently interrupted by the pylons. Additionally, because the road sectionscan be cantilevered from the pylons, multiple road sectionsmay be supported on a single pylon. For example, as described in greater detail with respect to, multiple road sectionsmay be easily supported by a single pylon. Such configurations may not be possible if each road section needed to be positioned on top and/or centered over a pylon.

illustrates an example road sectionof the elevated roadway. The road sectionmay include a joist structure, a road memberabove the joist structureand supported by the joist structure, and first and second side barriers,along first and second sides of the road member. The road sectionshown inmay be a standardized structure, such that many identical or similar instances of the road sectionmay be joined together and supported by pylons to produce the elevated roadway shown in.

The road membermay be adapted to receive and/or support a four-wheeled roadway vehicle, such as the vehicles(),(), and,() described herein. A “four-wheeled roadway vehicle” may refer to a wheeled vehicle that can move under its own power and freely maneuver along the roadway (e.g., without a track, rail, or other physical-contact based guide mechanism). The road membermay also be adapted to receive and/or support other types of vehicles, including vehicles with different numbers of wheels (e.g., one wheel, two wheels, three wheels, or more than four wheels), construction vehicles, four-wheeled roadway vehicles that are adapted for non-passenger use (e.g., for carrying cargo or other payloads), emergency vehicles (e.g., autonomous or human-operated police cars, ambulances, firetrucks, etc.), or the like.

The road membermay be made of or include concrete or any other suitable paving material (e.g., asphalt, bituminous road). Also, the road membermay lack rails or other mechanical guides that physically steer or guide the vehicles. Accordingly, the road membermay define a substantially flat or featureless surface that allows vehicles to freely drive and navigate along the roadway. The road membermay have any suitable dimensions to accommodate the vehicles for which the transportation system is designed. For example, the road membermay have a length dimensionthat corresponds to and/or is based on the length of the joist sections (which may be standardized to 50 feet or 33 feet, as described above, or may be any other suitable length). The road membermay also have a width dimensionof 130 inches (or any other suitable width). The width dimensionmay be configured to allow two vehicles to ride abreast or to pass each other on the roadway. For example, the width dimensionmay be at least twice the width of the vehicles, plus an additional safety margin (e.g., allowing 12 inches between vehicles and between vehicles and the side barriers). The road membermay also include systems and/or components embedded in or otherwise attached to the road memberto assist in vehicle navigation along the roadway. For example, markers that are visible and/or electronically detectable by vehicles may be embedded in and/or attached to the road member. Such markers may help the vehicle steer along a desired path, inform the vehicle where it is on the road member(and where it is along the roadway more generally), allow the vehicle to determine speed and/or other motion parameters, or the like. In some cases the markers are magnets or magnetic materials (e.g., steel, iron) that are embedded in the material of the road member.

The side barriers,may be formed of or include concrete, and may be integrally formed with the road member. For example, the side barriers,and the road membermay define at least part of a monolithic road structure that is formed by pouring or molding concrete into one or more metal forms. Road supports (e.g., road supports,,) may also be part of the monolithic road structure that also forms the road memberand the side barriers,. The road member, side barriers,, and the road supports may include reinforcing materials embedded in or attached to the concrete, such as rebar, straps (e.g., metal straps), bars, beams, brackets, or the like. As used herein, “rebar” may refer to steel reinforcement bars that may be at least partially embedded in or attached to a matrix material (such as concrete) to provide structural reinforcement to the matrix material. The side barriers,may have a heightabove the road member. The heightmay be selected at least in part based on the size and configuration of the vehicles that will ride on the roadway.

Because the side barriers,are integral with the road member, the road sections may define a continuous trough-like structure that prevents or limits water, debris, or other objects from falling off of the elevated roadway onto the ground or other underlying objects. To help remove rain water or snow melt (or other precipitation) from the road member, the road sections may include openingsin the road member(which may be covered by grates) that communicate with one or more conduitsbelow the road member. The conduitsmay extend parallel to the joists that support the road memberand may carry water from the road memberto a water outlet of the roadway. Water outlets may be integrated with the pylons and may be above, at, or below ground level. For example, the water outlets may drain to water detention planter boxes that are integrated into reinforcement sleeves around the base of the pylons (e.g., above grade), bioswales or basins on-grade, or directly into a storm system (e.g., a municipal storm system) below grade.

The conduitsmay also act as water reservoirs in case of clogged or blocked outlets or storm drain overflow. Accordingly, the conduitsmay be configured to have a particular internal volume that meets or exceeds any applicable storm water retention regulations, standards, and/or engineering best practices. In some cases, the roadway may include other reservoirs to supplement the volume of the conduitsthemselves. Additional details of water outlets are described herein with respect to.

The road sectionmay also include fencingextending above (and optionally extending from a top surface of) the side barriers,. The fencingmay include fence postssupporting one or more cablessufficient to comply with prevailing building codes and safety requirements. The fence postsmay be secured to the side barriers,to provide structural support for the fencing. For example, the fence postsmay be at least partially embedded in the concrete of the side barriers,(and thus embedded in or part of the monolithic road structure), bolted to the side barriers,, or otherwise secured to the side barriers,. The fencingmay have sufficient size and strength to arrest a fully loaded vehicle travelling at a target speed (e.g., a maximum planned vehicle speed, with a suitable additional margin). Accordingly, in the unlikely event of a collision between a vehicle and the side barriers,and the fencing, the vehicle may be safely contained on the roadway.

The fencingmay also be adjustable to different heights above the side barriers,. The adjustability of the fencing height may facilitate or enable several features. For example, the fencingmay be positioned at different heights along different segments of the roadway, such as higher along the outside of a turn or in environments where additional fencing height is necessary or desirable. As another example, the fencingmay be used for worker safety during construction and/or maintenance of the elevated roadway. Fencing for worker safety may have different requirements than fencing for roadway safety. Accordingly, the adjustable fencing allows the fencing to be positioned at a first level during construction and commissioning of the roadway (e.g., when workers may be on the road member), and at a second level (which may be lower than the first level) when the roadway is being used for vehicle traffic. The fencing, including the fence posts, cables, or both) may also be designed so that it can be used as a tie-off point for safety harnesses. More particularly, the fencingmay have sufficient strength ratings to meet or exceed fall protection safety standards (e.g., which may be applicable during construction and/or maintenance of the elevated roadway).

The roadway may also include one or more additional conduitsfor routing or otherwise carrying other materials, such as wiring, along the roadway. Wires from the additional conduitsmay provide power and/or communications to devices along the roadway. Such devices may include, without limitation, lighting, sensors (e.g., for sensing vehicles, traffic, weather or environmental conditions), communications equipment, or any other types of electronic equipment. While one additional conduitis shown, there may be any number of additional conduits supported by the roadway. The additional conduits may also be unrelated to the function of the roadway or transportation system. For example, electrical, water, telecommunications, natural gas, or other utilities may be routed in additional conduits that are supported by the roadway.

As noted above, the road membermay be on top of and supported by a joist structure. The joist structuremay include multiple parallel joists(e.g., four parallel joists). The joistsmay be formed of any suitable material, such as steel, and may have any suitable shape and/or configuration. The parallel joistsmay be connected to one another via inter-joist cables, braces, or other structures. The parallel joistsmay also be formed of or include multiple joist sub-sections joined end-to-end to define a single joist. Thus, for example, each of the four parallel joistsmay be formed of or include one, two, three, four, or more joist sub-sections. The connected parallel joistsmay constitute the joist structure of one of the road sections. As described herein, the joist structures of the road sections may be coupled to one another end-to-end to define a continuous roadway. This may include coupling the free ends of the joists of one road section to the free ends of the joists of another road section.

The road sectionmay also include wall sectionsthat may cover the joist structures. The wall sectionsmay be load-bearing or non-load bearing, and may prevent or limit access to the internal structures of the roadway by objects, animals, and individuals. The wall sectionsmay be removable and/or movable, however, to allow access to the joist structures, conduits, or other internal structures or components for construction, maintenance, or other purposes. The wall sectionsmay be formed from or include any suitable materials, including but not limited to metal, plastic, reinforced polymers, wood, glass, or the like.

is an exploded view of the road sectionof. The exploded view illustrates the parallel joiststhat form the joist structure, as well as the monolithic road structure (including the road memberand the side barriers,) that is supported by the joist structure, and the wall sections. As shown, the parallel joistsresemble parallel chord trusses (e.g., Warren trusses), though any other suitable joist or truss design may be used. As described herein, the road memberand side barriers,may be formed in-place after the joist structureis built, raised, and coupled to the pylons.

illustrate partial cross-sections of two example road sections,, respectively.illustrate how various differently shaped road members may be formed on top of the same joist structure.

illustrates an example of a road sectionthat defines a straight and level wearing surface. The road sectionmay include a monolithic road structure(defining a road member, sidewalls and fencing, as described above) that is formed on top of and supported by a joist structure. The joist structuremay include multiple parallel joists, as well as inter-joist members. The monolithic road structuremay be formed by attaching forms (e.g., metal molds) to the joist structure, where the forms define some or all of the shape of the monolithic road structure. Once the forms are in place, reinforcing materials (e.g., rebar, steel-fiber mesh, etc.) may be positioned in and/or above the forms, and concrete may be poured into the forms to encapsulate the reinforcing materials and ultimately form the monolithic road structure. In some cases, reinforcing materials such as reinforcing fibers may be mixed or otherwise incorporated into the concrete before the concrete is poured or otherwise deposited to form the monolithic road structure. The concrete may be a high-strength concrete with a compressive strength in a range of about 4-10 ksi, in some cases about 6 ksi. The forms may remain in place to add additional structural strength and/or support to the monolithic road structure. In other cases, the forms may be removed after the concrete is hardened.

The monolithic road structuremay define a road member, side walls, and road supports. The road supportsmay be part of the monolithic road structure (e.g., integral with the road memberand side walls), and may transfer load from the road memberto the joist structure. The shapes and sizes of the road supportsin any given road section may be selected to result in a desired attitude of the wearing surface. For example, as shown in, there are four road supports, each positioned on top of or otherwise being supported by a respective joist. The road supportsare all of the same height, resulting in the wearing surface of the road memberbeing parallel to a horizontal top plane defined by the joist structure(e.g., the road memberdefines a straight and level surface).illustrates another configuration of road supports that support a road memberin a non-parallel orientation relative to a horizontal top plane defined by the joist structure(e.g., the road memberis canted or banked).

illustrates an example of a road sectionthat defines a banked road member. Similar to the road sectionin, the road sectionmay include a monolithic road structure(defining a road member, side walls and fencing, as described above) that is formed on top of and supported by a joist structure. The joist structuremay include multiple parallel joists, as well as inter-joist members. The monolithic road structuremay be formed by attaching forms (e.g., metal molds) to the joist structureand forming the monolithic road structurein the forms using concrete and reinforcing materials, as described above.

The monolithic road structuremay define a road member, side walls, and road supports. Whereas the monolithic road structuredefined a horizontal wearing surface, the road membermay be pitched to define a pitched or banked wearing surface. The pitched road membermay define a portion of a banked turn section of the roadway. In order to produce the pitched road member, the road supportsmay have differing heights to produce the desired wearing surface angle. In this way, the same joist structures can be used to support numerous different road member configurations, orientations, and/or attitudes. More particularly, the same joist structures can be used for forming straight and level road sections, as well as banks, curves, hills, or other road profiles. In this way, the joist structures may be highly modular so that complex road profiles may be produced by forming multiple differently shaped monolithic road structures on top of standardized, uniform joist structures.

The road supports(and road supports,) may be continuous along the length of the monolithic road structures (e.g., continuous into the page), and thus may resemble elongated beam-like structures. In other examples, the road supports resemble pillars, and a series of pillars extends along and is supported by each joist structure to support the road member.

The road sections,may both have substantially the same width. For example, the width dimensions() and() may be the same. Because the monolithic road structures can be molded into many different shapes and configurations, the position of the monolithic road structures relative to the joist structures need not be uniform. For example, in, the monolithic road structureis centered above the joist structure. By contrast, inthe monolithic road structureis off-center above the joist structure. More particularly, the monolithic road structuredefines a first overhangthat is greater than a second overhangon the opposite side of the roadway. By allowing the joist structures to be off-center from the monolithic road structures, greater design flexibility is achieved because a larger range of road profiles, turns, banks, or other shapes or features can be provided using a uniform, modular joist structure (e.g., without having to modify or customize the joist structure for each road section).

illustrates a cantilevered road sectionsupported in an elevated position by a pylonthat extends vertically from a ground anchor.further illustrates the cantilevered configuration of the road sections, demonstrating how the road sections need only be supported along one side, and how the road sections need not be supported from directly below (e.g., centered below) the road sections.

The road sectionmay be coupled to the pylonby a bracketor any other suitable connector. For example, and as described herein, the bracketmay include a mounting platethat is secured to the pylonby anchors. The anchorsmay be rods, bolts, bosses, or any other suitable mechanism by which a bracketmay be attached to the pylon.

The pylonmay be secured to a ground anchor(or, in some embodiments, the ground anchor may be part of the pylon). The ground anchormay be formed of or include reinforced concrete that is formed in-place or otherwise positioned below ground level. A reinforcement sleevemay be formed about the base of the pylon. The reinforcement sleevemay be formed from or include a metal (e.g., steel) sleeve or jacket that surrounds a base of the pylon. In some cases, the reinforcement sleeveis formed from or includes concrete. In some cases, the reinforcement sleeveincludes a metal sleeve with concrete formed inside the metal sleeve and around the base of the pylon. Other configurations are also possible. For example, the reinforcement sleevemay include various types of energy-absorbing materials between an outer sleeve member (e.g., a metal tube) and the pylon. Such materials include without limitation foam, metal energy-absorbing structures, liquid (e.g., water), or the like.

Reinforcement sleevesmay be at least partially hollow or otherwise define internal volumes or chambers. The internal volumes of the reinforcement sleevesmay be used for water retention purposes. For example, water conduits that carry water away from a road surface may extend through the pylonand exit into or through the internal volumes of the reinforcement sleeves. Accordingly, if the amount of water that needs to be removed from a road surface exceeds the capabilities of the water outlet (e.g., if the volumetric flow rate of the water on the road surface exceeds the volumetric flow rate capability of the water outlet), water can temporarily back-up into the internal volumes and drain out in due course.

The reinforcement sleevemay be configured to help prevent or mitigate damage to the pylonin the event of an impact. For example, pylonsmay be positioned along or near a conventional surface road where vehicles may collide with the pylons in the case of accidents. Accordingly, the reinforcement sleevemay help absorb and/or dissipate energy from vehicles and minimize or eliminate structural damage to pylons.

illustrates additional details of the pylon, and in particular how conduits may be at least partially embedded in the pylonto carry water, wires, pipes, or other objects between a road surface and the ground. The pylonincludes a first conduitand a second conduit(though this is merely exemplary, and the pylonmay include more, fewer, or different conduits). The first conduitmay define an inletproximate the top of the pylon, and an outletproximate the bottom of the pylon. The second conduitsimilarly includes an inletproximate the top of the pylonand one or more outlets,proximate the bottom of the pylon.