Speeds Affect Crosswalk Visibility

Field of Vision at Different Speeds

As a driver’s speed increases, their peripheral vision narrows severely.   [Graphic via LADOT Vision Zero Report]

GOOD: RRFB

RFFBs are installed at both entrances of the crosswalk located underneath pedestrian signs. The RRFB’s amber lights flash in a ‘wig-wag,’ ‘one-two,’ strobe-like pattern that catches motorists’ attention, alerting them to crosswalk activity.  RRFBs perform best on roadways with ≤4-Lanes, in speed zones ≤20 mph( speeds that offer the greatest field of vision to motorists), and in areas where motorist familiarity with the crosswalk location is high.  With a lower cost, the RRFB is an attractive entry-level safety option.  However, RRFBs are a newer MUTCD traffic control device and some motorist confusion has been reported.

At either higher speeds or close range or vehicular obstructions,  RRFB can be a Good Safety Treatment but still be less effective, since they are located at the crosswalk entrances & not directly in the motorist field of view. 

For crosswalks with ≥2-Lanes, in ≥20 mph speed zones, and where commuter or highway cross-traffic exists (i.e., out-of-towners), flashing LED warning signs are an ideal solution. LED signs simply and elegantly communicate the message that a pedestrian is inside the crosswalk by reinforcing existing traffic warning measures. They are non-intrusive, as signs must already be used at crosswalks.

LightGuard’s flashing MUTCD compliant signs contain 96 high-intensity LEDs, greatly enhancing the sign’s visibility to the motorist. They flash only when a pedestrian is present and increase motorist yielding. LED signs can have active or passive detection, be paired with in-roadway warning lights or used as stand-alone systems. LED signs are budget-friendly, easy-to-install and offered in solar, A/C and wireless solar.

M11 LED LightStar™ In-Roadway Warning Light Installation

For crosswalks on ≥2-Lane roadways in ≤45mph speed zones, In-Roadway Warning Lights (IRWL) are the most effective method at alerting the motorist. IRWLs illuminate the crosswalk lines—visually reinforcing the crosswalk, and alert the motorist up to 1,000 feet in advance using our proprietary Enlighten1 flash rate. Coupled with LED signs, IRWLs provide the maximum level of pedestrian safety and warning to the motorist. IRWLs also offer the highest level of visibility within the field of vision at all speeds. They are the most reliable method at alerting the motorist in severe weather, on wide roadways with no center dividers, and at night, when pedestrians’ need for safety is greatest.

LightGuard’s in-roadway warning lights alert motorists 1,000 feet in advance of the crosswalk

• In-pavement LED traffic calming devices have evolved and are becoming more effective with less maintenance issues
• Studies using LightGuard’s in-pavement LED products show improvements in drivers yielding to pedestrians and better yielding at night4
• In-pavement warning lights are visible at all speeds, even when drivers’ peripheral vision narrows with speed

Field of Vision at Different Speeds with IRWL Lights

NOTE: In-roadway warning lights are visible at all speeds. [Graphic via LADOT Vision Zero Report with modifications by LightGuard]

In-Roadway Warning Light systems offer the greatest design flexibility and help overcome crosswalks with limited visibility, obstructions, curves in the roadway and where crosswalk approaches are hidden from the motorists’ view. LightGuard’s Smart Crosswalk™ IRWL is a highly configurable system that can be used with advanced controllers, radar devices, push buttons, LED signs, pedestrian detection bollards and solar power. IRWLs are ideal for use at parking structure exits, building entrances, airports, employee crossings and other locations where pedestrian safety is a concern.

Motion detectors, IRWLs and flashing LED signs are used at an underground parking garage exit to alert motorists to the presence of pedestrians on the sidewalk. Trace Loft building, Seattle, Washington.

4-Lane Smart Crosswalk IRWL system with automatic pedestrian detection bollards. Marco Island, Florida

With the Broadest Application, Time-tested IRWLS Are Lightguard Systems’ Most Specified Lighted Crosswalk System

Shopping mall entrance with multiple parking and crosswalk access points. The Outlets at San Clemente, California. Installation includes: custom bronze colored bollards; flashing 9X LightStar™ in-roadway warning lights, and flashing LED pedestrian signs.

The Zone of Convergence

Only LightGuard’s IRWL light beams can be directionally aimed at the approaching motorist’s line of sight, merging to form a blanketed area of light that we call ‘The Zone of Convergence.’ LightGuard’s IRWLs flash at the Enlighten1™ (meaning ‘to inform one’) rate which was developed in conjunction with the UC Berkeley Vision Detection Laboratory. Enlighten1™ reaches a primitive part of the brain that responds to danger and is photosensitive epilepsy safe.

Aesthetics Matter

The sleek, low profile of LightGuard’s IRWL system on the curb and in the street appeals to a minimalist sense of design. Whereas erecting a huge mast arm across the roadway, or crowding the curb with more traffic controls is contrary to every design idea we as a modern society are accustomed to. Undergrounding power lines and utilities is requisite to all new residential and urban design. The same design sensibility should also be applied to pedestrian safety.

In-roadway warning lights are low profile, appealing to a minimalist design aesthetic.

In contrast, HAWK beacon traffic control devices clutter the roadway and cost roughly 4X more $$$$ than in-roadway warning lights, even before installation costs are considered.

Studies Using LightGuard Systems’ IRWL

LightGuard Systems, inventors and pioneers of in-roadway warning lights have had numerous studies conducted using our IRWL system. In a study conducted by Whitlock & Weinberger Transportation Inc., April 1998, LightGuard’s Smart Crosswalk™ IRWL system increased driver yield rates to pedestrians from 20 percent to 95 percent in the evening.4 LightGuard’s products can be customized to fit any uncontrolled marked crosswalks, crosswalks marked with pedestrian, school or trail crossing signs, at locations such as:

• Urban mid-block crosswalks
• School zones
• Intersections with through lanes on major legs
• Multi-lane crosswalks
• Greenways
• Trail crossings
• Public parking garages
• Corporate campuses
• Rail Grade Crossings

LightGuard’s Solutions Include:

• Flashing LED safety systems for crosswalks and pedestrian crossings
• Automatic and manual activation devices that trigger a lighted system
• System controllers, data collection, storage and management devices
• Flashing LED Sign and Rapid Rectangular Flashing Beacon (RRFB) systems
• Flashing LED pedestrian, stop, yield, school zone and other signs

References

1. National Center for Statistics and Analysis. (2018, October). 2017 Motor Vehicle Crashes: Overview (Traffic Safety Facts Crash•Stats. Report No. DOT HS 812 603). Washington, DC: National Highway Traffic Safety Administration. https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/812603.
2. Bartmann, W. Spijkers and M. Hess, “Street Environment, Driving Speed and Field of Vision” Vision in Vehicles III (1991)
3. KLEWtv.com, Flashing lights at crosswalks confuse motorists at two busy intersections in Lewiston, by Shannon Moudy, (February 1st, 2017).
4. Whitlock & Weinberger Transportation Inc., An Evaluation of a Crosswalk Warning System Utilizing In-Pavement Flashing Lights (April 1998).
5. A. Leaf and David F. Preusser. Literature review on vehicle travel speeds and pedestrian injuries. (Washington, D.C.: U.S. Dept. of Transportation, National Highway Traffic Safety Administration, 1999).