FHWA-SA-06-12

Learn More

• Federal Highway Administration

 Office of Safety – Road

 Departure Safety:

 http://safety.fhwa.dot.gov/roadway_dept/

• Federal Highway Administration

 – Context Sensitive Solutions 

 National Web Site: 

 http://www.fhwa.dot.gov/csd/

• Roadside Design Guide.

 American Association of State

 Highway and Transportation

 Officials; 2002, Washington, D.C.

 https://bookstore.transportation.org/

• A Guide for Addressing Collisions

 With Trees in Hazardous Locations.

 National Cooperative Highway 

 Research Program Report 500,

 Volume 3; Transportation Research

 Board, 2003, Washington, D.C.

 http://safety.transportation.org/guides.aspx

Highway Safety and Trees:

The Delicate Balance

is available in a DVD 

format.

To request copies, please 

send an email to: 

report.center@fhwa.dot.gov

Or, you may contact:

FHWA RD&T Product

Distribution Center (PDC)

ARTI

9701 Philadelphia Ct

Ste. Q

Lanham, MD 20706-4436

Fax: 301-577-1421

Highway Safety and Trees:

The Delicate Balance

Highway Safety and Trees:

The Delicate Balance
An Ounce of Preventio

n

The best way to avoid crashes with trees is

to keep trees a safe distance from the 

roadside. Organizations that want to plant

trees should be encouraged to do so, but only 

in locations where the trees do not impede the 

driver's visibility and are not likely to be struck

by a vehicle. Every state and local highway

agency needs a policy for highway

landscaping that ensures that trees will be 

planted well outside of the street or highway

“clear zone.” Newly built neighborhoods can

be made safer by planting trees behind 

sidewalks or by using smaller trees or shrubs.

Driver education is also a critical component of 

an overall highway safety program. There are 

countless reasons why vehicles leave the 

pavement; a few examples are driver 

inattention and distractions, severe weather 

conditions, drowsiness, and attempts to avoid

other vehicles. Driving is a complex task, and

drivers need to be prepared and alert.

What About Existing Roadside Trees?

Highway agencies have many options to

reduce the potential of vehicles leaving 

the road. They may be able to flatten curves, 

add signage, and improve pavement 

markings. At locations where vehicles continue

to leave the road, removal of trees from the 

highest risk areas can be a cost-effective 

solution. Trees of special significance may be 

shielded with guardrail to soften the impact.

Of course, speed plays an important part in the 

severity of tree crashes. Many low-speed 

residential streets are known for their large,

stately trees. Trees on these streets do not 

usually present the same problems as trees

near high-speed roads and highways. 

High-speed roads and highways, both urban

and rural, should have roadsides free of trees

and other fixed object hazards. Regardless of 

the posted speed limit, the risk for vehicle

collisions with trees should always be assessed.

The Dilemma

While valued as a 

community asset

due to their beauty 

and environmental

benefits, trees are 

the single most

commonly struck 

objects in serious 

roadside crashes. 

Vehicle collisions with 

trees account for more 

than 4,000 fatalities 

and 100,000 injuries

each year. Efforts by 

highway agencies to

remove trees are often 

met with strenuous

objections by local

residents, concerned 

with preserving our 

natural resources and

the aesthetics they

bring to our

surroundings.

To further explore the 

issue of the safe

placement of trees

along our country’s 

roadsides, the Federal

Highway 

Administration

announces the 

availability of a

12-minute video 

entitled Highway 

Safety and Trees: The 

Delicate Balance. This

video encourages

highway agencies and

the public to work 

together to improve

safety while minimizing 

damage to the 

environment.

Initiate a Dialogue

Everyone is a

stakeholder when it 

comes to safety.

Highway Safety and

Trees: The Delicate 

Balance stresses that the 

design of highway

projects should be a 

cooperative effort 

involving the highway 

agency, concerned 

communities, 

organizations, and

individual citizens. Use

this video to initiate a 

dialogue. The video 

provides an opportunity

for all parties to recognize 

the benefits and risks

associated with trees. It 

discusses many solutions 

from roadway relocation 

to use of guardrail to

removal of trees from the 

most hazardous 

locations. No single

solution is appropriate for

all situations; every

potential solution

deserves discussion.

Use Highway Safety and Trees:

The Delicate Balance effectively at:

• State and local highway agency meetings

 where policies related to tree planting, 

 removal, or mitigation are established.

• Public hearings on proposed construction 

 projects that may include the removal of 

 trees to improve safety.

• Town meetings to describe the issues

 associated with trees and roadside 

 safety, and to encourage cooperation 

 when addressing these issues.