FHWA

Articles, guides, and products tagged "FHWA" — a combined view of every catalogue resource on this topic.

User guide

Defensive riding in mixed motor traffic: lane positioning, primary vs secondary position, door zone, right hook + left cross at the intersection, SMIDSY / look-but-failed-to-see — how to avoid conflicts with cars

Unlike braking technique, cornering, or night riding, a separate safety layer is the **strategy of interacting with motor traffic**: where to position yourself in the lane, how to read drivers before an intersection, where the door zone sits, what right hook and left cross are, and why statistically the **intersection** — not the straight section — is the more dangerous segment (NACTO: >40% of urban bike fatalities in 2022 happened at intersections; UK DfT 2022: e-scooter casualty rate is three times higher than for pedal cycles). This guide transfers to the e-scooter the classic principles of vehicular cycling (John Forester, *Effective Cycling* 1976, MIT Press 7th ed. 2012), Smart Cycling of the League of American Bicyclists, the NACTO Urban Bikeway Design Guide 3rd ed. 2025, the AASHTO Guide for the Development of Bicycle Facilities, ROSPA UK road-safety guidance, IIHS, and AAA Foundation research. Covers: lane-positioning theory (primary vs secondary position; why 'as far right as possible' is the worst strategy); door zone (12-27% of urban bike collisions — Wikipedia; Dutch Reach countermeasure); right hook (a turning vehicle crosses the bike lane), left cross (an oncoming driver turns across your path); SMIDSY / look-but-failed-to-see as a perceptual phenomenon (Hurt Report 1981 motorcycle baseline, 75% of motorcycle crashes involve a passenger car, 66% are ROW violations); 5 active-signalling rules (positioning + eye-contact + speed-modulation + escape-path + worst-case escape); why a bike lane is not always safer than the road; how to ride with the flow (vehicular) vs in a facility (segregated); a 30-minute practice drill.

13 min read

User guide

E-scooter braking technique: progressive squeeze, threshold braking, weight transfer, dry vs wet, regen integration

An e-scooter's stopping distance isn't a brake spec — it's the sum of the rider's reaction distance (≈1.5 s × speed) and physical braking distance ½v²/(μg), which grows quadratically with speed: at 25 km/h reaction-plus-braking is ≈14–15 m on dry, at 45 km/h it's already 30–35 m, at 65 km/h over 60 m. The tire-road friction coefficient μ_dry ≈0.7 on clean asphalt drops to μ_wet ≈0.3 in rain, μ_paint ≈0.1 on fresh markings, and μ_steel ≈0.1 on wet manhole covers — meaning the same speed needs two to seven times more distance. Under a hard stop, weight transfers forward to 70–80 % because of the rider's high CoG and the e-scooter's short wheelbase, so the front mechanical disc does the bulk of the work and the rear (mech or regenerative) helps. Threshold braking means decelerating just below the lockup point, because μ_static > μ_kinetic. Progressive squeeze (force ramping over 0.2–0.3 s) lets weight transfer to the front wheel before full torque is applied — otherwise the front locks before it's loaded and you go over the bars. Regenerative braking delivers up to 20 % of mechanical peak and **vanishes at low speed** (no back-EMF), so an emergency stop without mech brakes is impossible. This guide is drill-oriented: physics, weight transfer, progressive vs grab, dry vs wet vs paint vs steel, regen integration, a 4-step emergency-stop protocol. ENG-first sources: MSF Basic RiderCourse Quick Tips, IAM RoadSmart, RoSPA, NHTSA/FHWA stopping-distance data, IIHS friction tables, Cycling UK braking guide, Park Tool / Sheldon Brown bicycle dynamics, Helsinki TBI series (PMC 8759433).

14 min read

User guide

Riding an e-scooter at night: visibility as a three-component system, eye dark adaptation, conspicuity around cars, route planning

76% of US pedestrian and 56% of US bicyclist fatalities happen in darkness, dusk or dawn (NHTSA / FARS), and the Austin Public Health / CDC e-scooter injury study found the typical injured rider is a male aged 18–29 riding on the street at night. This guide moves night risk from the «hope they see me» bucket into the managed-risk bucket: visibility as a **three-component system** (active lights + passive retroreflectors + conspicuous clothing), the physiology of dark adaptation (5–10 min for cones, up to 30 min for full rod adaptation — Webvision NCBI), **biomotion configuration of retroreflectors** (Wood et al., QUT Vision and Everyday Function: retro material on ankles/knees/wrists increases driver recognition distance 3× vs a vest with the same area and 26× vs all-black clothing), the difference between detection and recognition in driver perception, front-light modes by lumens and context (Cycling UK: 50–200 lm for lit streets, 600+ lm for unlit roads, 1000+ for high speed), German StVZO § 67 and UK Highway Code rule 60 as the two regulatory poles, route planning with lit streets vs dark cut-throughs in mind, protocol for losing your front light mid-ride, the alcohol + night risk (PMC: 63% of nighttime riders alcohol-involved vs 22% daytime, 77% head/face injuries with alcohol vs 57% without). ENG-first sources: NHTSA Pedestrian Safety + Bicycle Safety countermeasures, FHWA EDC-7 Nighttime Visibility, Webvision (NCBI), Wood et al. biomotion studies, UK Highway Code rule 60, German StVZO § 67, Cycling UK light guide, PMC e-scooter alcohol/nighttime studies.

14 min read