Human Factors Guidelines for Road Systems 2021 Update, Volume 1: Updated and New Chapters (2022) / Chapter Skim
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Pages 143-160
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From page 143... ...
HFG BICYCLISTS VERSION 2.1 29-1 B CHAPTER 29 BICYCLISTS Signals and Signal Timing for Bicycles at Intersections ........................................................... 29-2 Markings for Bicycles at Intersections ......................................................................................
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From page 144... ...
HFG BICYCLISTS VERSION 2.1 29-2 SIGNALS AND SIGNAL TIMING FOR BICYCLES AT INTERSECTIONS Introduction Design for traffic signals at intersections are generally determined by motor vehicle use. This creates systems that are not timed for, nor designed to detect the presence of, other road users such as bicyclists, because they use the same roads and signal displays but have different operating characteristics and needs.
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From page 145... ...
HFG BICYCLISTS VERSION 2.1 29-3 Discussion Signal Timing: Whether in a road or bike lane, more experienced bicyclists can be comfortable entering intersections during mid-to-late green intervals, others tend to slow down when approaching a green signal in order to start at the beginning of a green interval (1)
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From page 146... ...
HFG BICYCLISTS VERSION 2.1 29-4 MARKINGS FOR BICYCLES AT INTERSECTIONS Introduction Bicyclists are particularly vulnerable at intersections because they can be less noticeable or easy to miss due to their size. Further, large vehicles with increasingly wide A and B pillars, as well as drivers' use of interactive screens within vehicles, increase the likelihood that a driver will fail to notice a bicyclist.
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From page 147... ...
HFG BICYCLISTS VERSION 2.1 29-5 Discussion When planning the layout of intersections, designers must consider potential conflicts among all road users, not only between motorists. Though bike lanes next to left-turn lanes, as in the figure above, can help position bicyclists and reduce merging confusion between them and motorists.
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From page 148... ...
HFG BICYCLISTS VERSION 2.1 29-6 BICYCLE LANES Introduction Bicycle lanes refers to conventional and buffered bicycle lanes that use pavement markings to designate a portion of the roadway exclusively for bicyclists' use. While designated bicycle lanes without a physical separation are not the preferred treatments for the majority of people who ride bikes, they can provide additional width to reduce crash potential by separating motor vehicles from bicycles, reducing ‘dooring' from bicycles colliding with parked car doors, and increasing motor vehicle drivers' awareness by indicating where they can expect bicyclists to be traveling.
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From page 149... ...
HFG BICYCLISTS VERSION 2.1 29-7 Discussion Bicycle lanes designate a space for bicyclists using pavement markings. In general, bike lanes enable bicyclists to ride at their preferred speed without interference from motor vehicle traffic and can facilitate predictable behaviors and movements between bicyclists and motor vehicles (1)
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From page 150... ...
HFG BICYCLISTS VERSION 2.1 29-8 SEPARATED BICYCLE LANES Introduction Separated bicycle lanes are one or two-way exclusive bikeways parallel to the roadway yet physically separated from moving traffic. Separated bike lane barriers can consist of curb separations, landscaped medians, flexible delineators or bollards, or other vertical structures.
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From page 151... ...
HFG BICYCLISTS VERSION 2.1 29-9 Discussion Separation of bike lanes from motor traffic may be desirable for various reasons such as high traffic speeds, high traffic volumes, aggressive motor vehicle behavior, or general lack of consideration by drivers towards bicyclists' use of roads (5)
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From page 152... ...
HFG BICYCLISTS VERSION 2.1 29-10 CONTRAFLOW BICYCLE LANES Introduction Contraflow bicycle lanes refers to bicycle lanes installed on the left side of a one-way street to give bicyclists the option to ride opposite the flow of traffic in a designated bike lane. Contraflow bike lanes may be considered in situations where travel in a with-flow bike lane would result in substantial out-of-direction travel and can be installed around high bicycle use destinations to provide more direct access (1)
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From page 153... ...
HFG BICYCLISTS VERSION 2.1 29-11 Discussion Contraflow bike lanes are designed to allow bicyclists to ride in the opposite direction of motor vehicle traffic and are used to create a two-way bicycle street on a one-way motor traffic street (3)
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From page 154... ...
HFG BICYCLISTS VERSION 2.1 29-12 SHARED USE LANES Introduction Shared use lanes are lanes on the roadway that are designated for mixed use between bicyclists and motorists. Shared lane markings, also known as sharrows, are markings used to indicate the shared lane environment and promote proper bicyclist positioning.
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From page 155... ...
HFG BICYCLISTS VERSION 2.1 29-13 Discussion Shared Use Lanes: Shared use lanes can be used on bicycle boulevards, traffic calmed streets with a designed speed of less than 25 mph, on downhill segments (if space does not permit a wide downhill bike lane) , within single or multilane roundabouts, along front-in angled parking, and where street widths can only accommodate a dedicated bicycle lane in one direction (2)
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From page 156... ...
HFG BICYCLISTS VERSION 2.1 29-14 SHARED BUS-BICYCLE LANES Introduction Shared Bus-Bicycle Lanes refers to dedicated lanes with right-of-way restricted to the use of buses, bicycles, and sometimes right-turning vehicles. Increasingly, cities across the U.S.
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From page 157... ...
HFG BICYCLISTS VERSION 2.1 29-15 Discussion Shared bus-bicycle lanes (SBBLs) are lanes dedicated for use by both buses and bicyclists and often, right-turning vehicles at intersections (3)
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From page 158... ...
HFG BICYCLISTS VERSION 2.1 29-16 MITIGATING HEAVY VEHICLE CONFLICTS WITH BICYCLES Introduction The difference in mass and size between heavy vehicles and bicycles can contribute to serious bicyclist injuries or fatalities when conflicts between these two modes of travel occur. Heavy vehicle blind zones and reliance on mirrors for visibility make it difficult for heavy vehicle operators to observe bicyclists riding close to the vehicle, while bicyclists are often unaware of these visibility challenges and ride too close to the truck or engage in unsafe maneuvers.
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From page 159... ...
HFG BICYCLISTS VERSION 2.1 29-17 Discussion Heavy vehicle-bicycle crashes in urban settings were generally found to occur in locations with higher employment shares in freight-dependent industries (e.g., wholesale, transportation, warehousing, and retail)
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