Truck Lateral Protective Device (LPD) Resources
Note: the term "side guard" is used colloquially throughout this webpage and related materials, but refers to "lateral protective devices" and not to "underride" guards.
Truck lateral protective devices are vehicle-based safety devices designed to keep pedestrians, bicyclists, and motorcyclists from being run over by a large truck’s rear wheels in a side-impact collision.
The U.S. DOT Volpe Center is monitoring this technology’s adoption in the United States, and has conducted research and partnered with public- and private-sector fleets to help deploy lateral protective devices and other technologies that address the deadliest road crashes: those between large trucks and pedestrians or bicyclists.
While large trucks comprise 4 percent of registered vehicles, large trucks are involved in 10 percent of pedestrian and bicyclist fatalities. In 2018, these nonmotorist fatalities rose to 541, the highest since 1990.
The U.S. DOT Volpe Center is also assisting a national network of early adopters in the area of truck lateral protective devices and other truck safety technologies related to pedestrians, bicyclists, and motorcyclists—known as vulnerable road users.
This page is intended to offer general knowledge and resources for municipalities as well as private-sector businesses that are seeking information or considering adopting this technology.
During a crash with a truck or other vehicle with high ground clearance, vulnerable road users can fall into the exposed space between the front and rear wheels and suffer fatal crushing injuries.
Lateral protective devices work by physically covering that exposed space, shielding vulnerable road users from being swept underneath the truck’s rear wheels.
This technology can be retrofitted onto existing trucks or incorporated into new vehicle fleets.
Learn more by reading the Lateral Protective Device Technical Overview: Safety and Operational Considerations and the Lateral Protective Device Best Practice Specification.
Crashes involving large trucks are more likely to result in a pedestrian or bicyclist fatality than crashes involving passenger vehicles. Truck crashes are also more likely to be side-impact crashes.
Based on studies conducted in the United Kingdom, Australia, Sweden, and the Netherlands, lateral protective devices are an effective technology for reducing the number of vulnerable road user fatalities and the severity of injuries, especially for bicyclists.
- Following the national lateral protective device mandate in the UK, there was a 61 percent drop in cyclist fatalities and a 20 percent drop in pedestrian fatalities in lateral protective device relevant collisions with trucks.
Improving Fuel Economy
Aerodynamic truck side skirts (or underbody fairings)—a technology similar to lateral protective devices—are primarily designed to save fuel for trucks by decreasing air drag.
- Side skirts provide 4 to 7 percent fuel efficiency improvement (verified by EPA SmartWay).
- Annual fuel savings from installing a rigid side skirt can reach $5,000 for a long-haul tractor trailer, depending on mileage and speed.
While side skirts are primarily designed to reduce fuel consumption, this technology may also protect vulnerable road users in side-impact collisions.
A number of side skirt manufacturers have already verified that their panels can meet lateral protective device structural requirements with few or no modifications. Canadian and Dutch research also suggest that certain side skirts may provide protection that’s comparable to that of lateral protective devices. Thus, a dual-purpose lateral protective device/skirt may provide both vulnerable road user safety and fuel return on investment to the owner.
Lateral protective devices have been required standard equipment since 1979 in Japan, the 1980s in the European Union and China, and more recently in Brazil, Peru, and Mexico City. Canada conducted research for a national side guard standard from 2009 to 2013 and also began evaluating the viability of using aerodynamic side skirts for vulnerable road user safety.
There has been growing lateral protective device adoption in the United States at the local and private-sector levels, including dozens of private fleets and municipal or city-contracted fleets in over a dozen cities from coast to coast.
The U.S. DOT Volpe Center has a significant library of literature on truck lateral protective devices and is building a national network of adopters in the areas of lateral protective devices, high-vision cabs, automatic emergency braking systems, and other truck safety technologies relevant to vulnerable road users. (For more information, contact Dr. Alexander Epstein at Alexander.Epstein@dot.gov.)
The following U.S. resources offer an introduction to this research:
- FMCSA Study of Truck Lateral Protective Devices to Reduce Pedestrian Fatalities
- Boston Truck Side Guard Ordinance
- Cambridge Safer Truck Initiative: Vehicle based strategies to protect pedestrians and bicyclists (March 2016)
- NYCDOT Clean Trucks Program Side Guard Vendor List
View web page
- Review and Analysis of Potential Safety Impacts of and Regulatory Barriers to Fuel Efficiency Technologies and Alternative Fuels In Medium- and Heavy-Duty Vehicles (June 2015)
- Truck Side Guard Ordinance: Boston, MA (FHWA case study, March 2017)
View PDF or HTML page
- Truck Lateral Protective Device Technical Overview: Safety and Operational Considerations (fact sheet)
- Truck Lateral Protective Device Best Practice Specification
- Truck Side Guards for Vision Zero (December 2014)
- Vision Zero San Francisco Truck Side Guard Initiative (May 2016)
- Transport Research Laboratory: Sideguards on Heavy Goods Vehicles: Assessing the Effects on Pedal Cyclists Injured by Trucks Overtaking or Turning Left
- Transport Research Laboratory: Analysis of Police Collision Files for Pedal Cyclist Fatalities in London, 2001-2006
- SWOV: The Safety of Trucks; An accident and measures analysis commissioned by the Dutch Transport Operators Association
- Dutch Road Safety Research Institute: Closed Sideguards on Trucks: Less Fuel Consumption for Trucks, Safer Feeling for Vulnerable Road Users
- National Research Council Canada: Side Guards for Trucks and Trailers: Phase 1: Background Investigation
- Great Britain Department for Transport: Integrated Safety Guards and Spray Suppression: Final Summary Report
Lateral Protective Devices: How They Work
U.S. DOT Volpe Center crash tests demonstrate how lateral protective devices can interact with vulnerable road users when they collide with large trucks.
Disclaimer: The following demonstration video was created as part of early research into lateral protective device technology. The video is posted here to advance scientific knowledge and technology transfer, with all of its usefulness and inherent shortcomings. It is not intended to be pre-regulatory in nature, nor to provide evidence in support of regulatory action.
Lateral Protective Devices: Saving Lives, Saving Fuel
U.S. DOT Volpe Center engineer Alex Epstein presents the idea of using lateral protective devices as a means to make trucks safer.
Protecting Pedestrians and Bicyclists, One Safer Truck at a Time
U.S. DOT Volpe Center engineer Alex Epstein discusses lateral protective guards and other technologies that address the deadliest road crashes: those between large trucks and pedestrians or bicyclists.
- Boston passes the nation’s first ordinance requiring lateral protective devices on trucks.
- New York City becomes the largest municipal fleet in the nation to install lateral protective devices, starting with 240 city trucks in 2015, then signing legislation requiring lateral protective devices on 10,000 vehicles by 2024.
- NYC’s Vision Zero program provides incentives to private waste hauling companies to become early adopters of lateral protective devices.
- Cambridge announces a safer truck partnership with the Volpe Center.
- The University of Washington installs lateral protective devices on its campus box truck fleet.
- New York City Fleet installs lateral protective devices on 370 City trucks, with over 1,000 installs to be completed by the end of FY17, making it the largest rollout of this technology in the U.S. so far.
- Seattle announces the adoption of lateral protective devices on its city fleet.
- Washington, D.C., announces its entire heavy-duty fleet has been equipped with lateral protective devices.
- Chicago passes an ordinance requiring city contractors to install lateral protective devices and convex mirrors on large trucks.
- Portland, Oregon, announces that waste and recycling contractors will need to implement LPDs by 2022.
- Waste360 (7/23/18): Is Widespread Side Guard Implementation on the Horizon?
- The Harvard Gazette (2/21/18): Harvard Rolls Out Program to Protect Pedestrians and Cyclists
- The National Law Review (4/26/17): Truck Side Guards Increase Safety
- Streetsblog USA (10/31/16): Why American Trucks Are So Deadly for Pedestrians and Cyclists
- CBC News (9/8/16): Mayor Calls on Transport Canada to Make Side Guards Mandatory on Big Trucks
- Volpe News (2/22/16): Side Guards Safety Work Nets National Tech Transfer Award
- Government Fleet (6/23/15): NYC Mayor Mandates Side Guards for Refuse Trucks
- New York Daily News (2/9/15): City Truck Fix Aims to Stop Pedestrian Fatalities
- Wall Street Journal - Metropolis (2/9/15): NYC to Outfit 200 Trucks With Guards to Protect Pedestrians: Mayor Bill de Blasio
- NY1 News (2/9/15): Safety Guard Rails to Be Added to City Trucks
- Boston Magazine (9/9/14): Mayor Walsh Wants ‘Truck Side Guards’ on All Vehicles Contracted by the City
- Boston Magazine (9/16/14): Cambridge Is Also Looking at Installing Side Guards on Large Trucks
- Boston Globe (1/11/15): 20 of Boston’s Best New Big Ideas and Fresh Faces
- Volpe News (10/20/14): Cities Take Steps to Increase Bicyclist and Pedestrian Safety
- Volpe News (5/27/14): Engineer's Passion for Pedestrian and Bike Safety Leads to Partnership with NYC
- Volpe News (5/20/13): Engineer's Resourcefulness Drives Investment in Boston Bike Safety Initiative
The U.S. DOT Volpe Center, as a U.S. DOT agency, does not “certify” or “approve” lateral protective device products or services. Compliance with any applicable specifications or regulations is based on self-certification by the manufacturer.
The information presented on this webpage and in related materials represents the best technical judgment of U.S. DOT Volpe Center staff based on their independent and objective technical analysis and expertise, and is not to be misconstrued as statements of U.S. DOT policy or guidance.