| 1. | A pillarsupported elevated lane or bus traffic comprising a sequential array of pairs of mutually parallel and mutually opposing lightweight, prefabricated structural sections (3), preferably having a length of 1535 m, in which each pair of structural sections is erected with an intermediate free space of preferably between 0.5 and 1.5 m, and in which said structural sections (3) form the bus lane or a substratum therefor and are each provided with a respective lateral barrier (3c) and fender means (3b) inten ded for returning the bus to the drive lane upon given deviation from an ideal driving line, and in which the distance between mutually opposing structural sections and/o their respective lateral barriers (3c) when located in a curve increases substantially in inverse proportion to the radius of the curve; and in which the fender means include a stepped fender edge (3a) with which a bus is intended to come into contact upon given deviation from an ideal driving line, and an inclined surface (3b) which has a progressi¬ vely increasing slope towards the lateral barrier (3c) and which is intended to tilt and return the bus to the region of said ideal driving line when the aforesaid given devia¬ tion exceeds a given limit, characterized in that the fender means is an integral reinforcing and stiffening part of respective structural sections (3) , so that both the stepped fender edge (3a) and the inclined surface (3b) of progressively increasing slope form defining surfaces of respective structural sections. |
| 2. | An elevated lane construction according to Claim 1 , characterized in that the respective lateral barriers (3c) , at least at one of two mutually opposing structural sec¬ tions (3) , present such a distance to the outer side of the bus (10) that access can be had in an emergency to the space (11) located between the bus and the lateral barrier. |
| 3. | An elevated lane construction according to Claim 1 or Claim 2, characterized in that the lateral barriers are arranged to carry, sound absorbing means. |
| 4. | An elevated lane construction according to any one of Claims 13, characterized in that a space located between mutually opposing structural sections is arranged to accommodate means for contactless automatic bus control. |
Background Art
Traffic in the centres of the majority of the world's principal cities is reaching chaotic proportions. Certain cities have succeeded in alleviating traffic conditions by building expensive subways or underground vehicular lanes in tunnels. In other cases the authorities have utilized available road space to provide separate bus lanes and individual trolley-bus lines.
Collective traffic can also be separated from remaining traffic by constructing elevated drive lanes and tracks for one or more typres of transit vehicles above the streets. This method enables the collective traffic capacity to be increa¬ sed without the expense entailed by the construction of underground tunnelways and without needing to utilize valu- able existing road space. Such elevated traffic lanes inten¬ ded solely for collective traffic require but small space at ground level, are highly flexible with regard to span,- can be readily constructed quickly- and cheaply, and have- a high traffic capacity. Various types of elevated track-bound traffic systems are known to the art. Examples of such systems are found in SE-A-368.730, corresponding to US-A-3,376,830 (Bingham) ; SE-A-226.668 and SE-A-313.328 (both Pneuwais Development); US-A-3,209,702 (Lemoke) ; FR-A-2 203 336 (C.I.M.T.-Lorraine) ; DE-A- 2.309.088 (Baldelli) and DE-B-2.427.771 (Rheinstahl) . - Other solutions incorporating the use of elevated transit lanes with track-bound systems of modified design are described and illustrated, for example, in GB-B-1,495, 143 (Laing & Son); DE-B-2.331.445 ( Strabag Bau) ; and EP-A-0 010 733 (Parazader) .
Such elevated track-bound traffic systems, however, have the same disadvantages as all other track-bound traffic systems, namely that they are inflexible and incur high construction costs, and also require the application of comprehensive and labour-intensive control and monitoring systems. Consequently they do not provide a satisfactory solution to the traffic problems of large cities.
In conjunction with elevated traf ic, systems attempts have been made to design totally new vehicular traffic or transit means in which both the. vehicular transit means and the track along which the relevant vehicle runs are mutually adapted to create low air resistance and.a high safety factor, despite the relatively high transit needs employed. An example of one such transit system is described and illustrated in US-A-3,669,026 (Mouritzen) . In addition to the high construc¬ tion costs entailed, this transit system has the same dis- advantages as all other track-bound traffic systems, these disadvantages primarily including a high degree of inflexi¬ bility and the inability to adapt to differing traffic requirements.
In a pamphlet issued by Daimler-Benz AG in April 1979 and captioned "The O-Bahn, a system concept for solving local transport problems in industrialized and developed countries", there is described an elevated track system for bus traffic which incorporates lateral guide rails. In this system the transit vehicle, i.e. the bus, is fitted with separate guide rollers which engage the aforesaid lateral guide rollers of the elevated lane structure.
While this system may offer a satisfactory solution to the vehicle manufacturer who is able to effect design changes in the actual transport vehicles used as the need arises, it does not afford a satisfactory solution when desiring to use buses of conventional design on elevated bus lanes and when wishing to consider instead the particular problems which arise in respect of the design and construction of the elevated bus-traffic system in the fulfillment of the need to render such a system free from risk to the greatest possible extent in respect of the passengers using the system.
CH-B-402.921 (Bucher) describes the arrangement of vehicle so-called fender means in conjunction with crash barriers, comprising a stepped fender edge, with a progressi¬ vely increasing incline on the ender means and vehicle return means which engage the vehicle -wheels. This fender - means has the orm of a. separate element placed on a road
surface beneath a post-carried crash barrier. This publi¬ cation, however, does not provide a solution to the parti¬ cular. roblems encountered with elevated lanes for bus traffic.
Field of Invention
The present invention relates to a pillar-supported elevated lane structure for bus traffic, comprising sequen¬ tial arrays of two mutually parallel and mutually opposite lightweight prefabricated structural sections, preferably
15-35 m in length, assembled with an intermediate free space of preferably between 0.5 and 1.5 , these structural sec¬ tions forming the bus driveway or providing a substratum therefor and being provided with lateral barrier means and fender means for returning the bus to the driveway upon given deviation from an ideal driving line, the distance between opposing structural sections and/or the lateral barrier or fender means thereof in a curve increasing sub¬ stantially in inverse proportion to the radius of the curve, and the fender means including a respective stepped fender surface which is engaged by the vehicle upon minor devia¬ tions from an ideal driving line, and a profiled surface which has a progressively increasing angle of slope towards the lateral barrier and which tilts and returns the bus to the ideal driving line upon excessive deviation therefrom. One advantage afforded by an elevated lane system for bus traffic of this kind is that it can be used in heavily trafficated parts of a large city while at the same time enabling the superior flexibility of the bus in comparison with other types of public transport vehicles to be utilized to the full in those areas where traffic is not so dense and where the bus is able to leave the elevated highway and join the conventional road and street network of the city or town, optionally along separate lanes reserved solely for bus traffic.
Due to the presence of the fender means with its stepped fender edge followed by a pro iled surface of progressively increasing slope, the bus driver tends to ensure that the
bus follows an ideal driving- line, including permitted "wavering" deviations therefrom, because of the discomfort experienced by both the driver and the passengers when driving up onto the fender edge. In addition the bus is forcibly returned to the ideal driving line when devia¬ tions therefrom are excessive.
This elevated traffic lane construction also takes into account the problem relating to the so-called sweep- radius which determines the increase in lane width for respective inner and outer wheel tracks. In the case of a curve of comparatively large radius there is very little need to increase the lane width and any increase required will only entail some few percent of the total lane width. When the curve radius drops to the permitted minimum of about 30 m, however, the sweep area and therewith the need for a wider lane increases drastically. In such cases it may be necessary to increase the lane width by some tens of percent of the standard lane width. The aforesaid increase in lane width ensures - despite a considerable increase in sweep area, particularly in curves of " small radius - free and unimpeded driving of the bus without risk of damage to the bus from the lateral barriers.
Object of the Invention One object of the present invention is to provide an improved elevated lane construction for bus traffic of the aforesaid kind which avoids the aforementioned disadvantages inherent with known elevated traffic lane systems and other disadvantages encountered therewith; which can be constructed readily at low cost; which enables buses of conventional design to be used; and which increases passenger safety.
Another object of the invention is to provide an eleva¬ ted traffic lane construction in which in the event of an emergency, e.g. in the event of fire while holding the driving line, the bus can be quickly evacuated.
Brief Disclosure of the Invention
An elevated lane system for bus traffic constructed in
accordance with the invention is mainly characterized in that the fender means is an integral reinforcing and stiffe¬ ning part of a respective structural section, so that both the stepped edge and the progressively inclined profile surface form structural-section defining surfaces.
The invention enables the structural sections as a whole to be manufactured more readily and to more slender dimen¬ sions, this slender design of the sections meaning that they can be transported more easily to the construction site and facilitating their erection on the tall concrete pillars.
In addition, the improved strength properties of the sections increase the passenger safety factor, which is of essential importance in the case of elevated traffic lanes, where the risk of failure due to driving against the lateral barriers is naturally much greater than when driving along conventio¬ nal roads and highways.
In practice, the distance from the lateral barriers, at least at one of two opposing structural sections, to the adjacent side of the bus is preferably such as to provide access to the space between the barriers and the bus in the event of an emergency.
In this case an elevated lane construction intended for one-way traffic only obtains an asymmetric configuration. When the lane system is intended for lanes in contra-flow, however, corresponding access possibilities should be provided on both sides of the lane system, which results in a symmetric configuration about a centre line in the free access area between the structural sections.
An elevated lane system for bus traffic constructed in accordance with the invention is primarily intended for manually driven buses. One particular advantage afforded by the inventive elevated lane construction, however, is that it can be readily adapted for automatic vehicle control purposes. For example, the space between mutually opposing structural sections can be utilized to accommodate electric cables or like conductors which permit automatic, contact- less control of a bus with the aid of electronic devices.
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Alternatively, or in. addition thereto, the lateral barriers may also incorporate guide means of the aforesaid kind or, e.g., guide rails for mechanical guidance. Another important advantage afforded by the inventive elevated bus lane construction is that the lateral barriers act as a noise barrier, the fender means per se serving as a noise screen. The fender means may also incorporate separate sound absor¬ bing devices.
Other aspects of the invention will be apparent from the following description, which is made with reference to a number of selected embodiments thereof.
Brief Description of the Drawings
Figure 1 is a perspective view of a pillar-supported elevated bus-lane construction in accordance with the invention.
Figure 2 is a cross-sectional view of the elevated bus- lane construction shown in Figure 1.
Figure 3 is a cross-sectional view of a modified bus- lane of asymmetric configuration.
Figure 4, finally, is a plan view of a curve of short curve-radius incorporated in the elevated bus-lane construc¬ tion of Figure 1.
Description of Preferred Embodiments
An elevated lane 1 for bus traffic is carried on pillars 2 and comprises a sequential array of pairs of mutually parallel and mutually opposing prefabricated, lightweight structural sections 3 having a length of 24 , for example. The sections 3 of each pair of sections are mounted on respective pillar supports with an intermediate free space of, for example, about 0.9 m, this free space being bridged by respective spaces 4 and 5 which join together respec¬ tive opposing sections of each pair. The free space between opposing sections can be filled with a grid as shown at 7. The width of the bus 10 illustrated in Fig.. 1 can be assumed to be 2.6 , in which case the planar part of the lane located outwardly of the bus wheels and extending up to
stepped edge 3a of the lane constructio may measure rom 0.3 to 0.4 m. This means that the bus is able to deviate from an ideal driving line, i.e. a "wavering tolerance", to a corresponding extent on either side of said line before contacting or driving onto the stepped portion of the lane construction, which latter affords an unpleasant experience to both driver and passengers.
This wavering latitude with respect to minor deviations from an ideal driving line, however, is sufficient under normal conditions to permit the bus to be driven comfort¬ ably at relatively high speeds.
As illustrated in the cross-sectional view of Fig. 2 , the structural sections 3 exhibit outwardly of the stepped edge 3a an inclined surface of progressively increasing slope. This part of the section profile line serves as a fender means operative to tilt the bus and return it to the driving lane should the bus deviate excessively from the aforesaid ideal driving line.
This contour line 3b merges with a respective lateral barrier 3c, the main purpose of which is to prevent the. bus from leaving the elevated lane construction.
The fender means forms an integral reinforcing and stiffening part of respective structural sections 3, so that both the stepped fender edge 3a and the profile sur- face 3b exhibiting a progressively increasing slope form defining surfaces of respective structural sections.
In the embodiment illustrated in Fig. 2, the aforesaid lateral barriers 3c are provided with additional fender means 6 in the form of two semi-cylindrical elements, which may comprise rubber or a similar material.
In the embodiment illustrated in Fig. 2, the lateral barriers 3 are located at a substantial distance from the actual bus lane in a manner to leave a space between the sides of the bus and the respective lateral barriers, this space enabling the bus to be evacuated in an emergency, even with the bus located ut on the line. Because of the symmetrical configuration of the embodiment illustrated in Fig. 2, one such space is found on both sides of the bus.
thus permitting traffic to move in two directions on the elevated lane system.
Fig. 3 illustrates in cross-section a modified embodi¬ ment in which the structural sections 3 are of asymmetric construction. In this case, a free space 11 is found only on one side of the bus, outwardly of the bus door 10b illustrated in chain lines in Fig. 3 and shown in its open position. This lane system is thus intended for one-way traffic only. The Fig. 3 embodiment also incorporates additional fender means 6 in the form of elongated cylindrical elements adapted to contact the outer bus wheels 10a should the bus move further towards the lateral barrier 3c upon contact with the stepped edge 3a. The resilient fender means 6 are intended to return the bus to the correct drive lane.
Because of the asymmetric configuration of this eleva¬ ted traffic lane, it is not normally necessary to provide corresponding fender means on the opposite side of the lane, although such fender means may be provided on said opposite side if desired.
Fig. 4 illustrates in plan view a comparatively sharp curve of small radius. The figure illustrates the need of widening the lane located in such a curve, as a result of the increased sweep area of the bus. When the distance between mutually opposing lateral barriers measures, for example 3.6 m a curve of the illustrated kind needs to be widened by 0.3 m so as not to appreciably change the driving conditions.
The space 4 located between mutually opposing structu- ral sections 3 may accommodate an electric cable, a guide rail, contact rail or like device (not shown) to enable the bus to be controlled automatically with the aid, for example, of electronic and/or mechanical devices. Alterna¬ tively, or in addition, such guide and control means may be incorporated in the lateral barrier 3c and/or the fender means 6 carried thereby.
The lateral barriers- 3c may incorporate or form sound- screening means so as to act as sound barriers. The lateral
barriers may be constructed in different ways and provided with suitable sound absorption devices for achieving the aforesaid sound-damping effect.
Industrial Use
The structural sections of an elevated traffic-lane construction according to the invention are simple to manufacture and hence it is possible in many cases, without incurring high investment costs, to establish a separate factory or plant at or in the vicinity of an area upon which such an elevated lane construction is to be erected. The structural sections are mechanically strong and highly reliable despite their lightness in weight and slender design, which in turn facilitates their transportation to the construction site and the mounting of the sections on respective concrete pillars. The high mechanical-strength properties also afford additional safety in respect of the passengers, so that traffic using an elevated lane system according to the invention is able to travel with the minimum of risk.