The advent of solar energy utilization in highway infrastructure around the country has been increasing in

recent years. Right of Ways (ROWs) have several advantages for energy development such as the existing

electrical infrastructure aligned with the major highways, a secured boundary, and easy maintenance access. It

has been identified by various Departments of Transportation (DOTs) and the Federal Highway Administration

(FHWA) that solar array deployment along the ROW is possible after adequate site evaluation and impact

study. With higher solar insolation available, CDOT can generate electricity from solar arrays on its ROWs

across much of the State of Colorado. Political climate, public cooperation with energy providers, commitment

of utility companies and potential impacts are some of the major concerns in successful solar array deployment.

The potential impact of photo voltaic (PV) arrays on driver safety, highway operation and maintenance, and the

environment are the focus of this research study. Changes in driver’s expectations, glare, maintenance practices

due to snow drifting along the roadside, and local ecosystems are some of the impacts that are evaluated in this

report.

To understand the potential impacts on driver safety, environmental resources, and maintenance operations, case

studies are presented from national and international projects. A base line study was performed pertaining to the

current ROW’s physical characteristics, operational conditions, regulatory requirements and PV array design

criteria. Factors associated risk impacts are analyzed qualitatively as well as quantitatively. Mitigation measures

are recommended to minimize the undesirable impacts in the planning, design, construction, operation and

maintenance of solar array. This document provides guidance for CDOT Management, Project Engineers,

Operation and Maintenance personnel and energy generators who are interested in installing and maintaining PV

arrays in the CDOT ROW. The following are the main objectives of this project:

 Develop a general model of a solar highway focusing on user safety and maintenance activities

 Study and analyze the impact of highway solar array on driver’s safety

 Study and analyze the impact of highway solar array on road maintenance

 Evaluate and assess the impact of the highway solar array on the environment

 Identify and list the critical risk factors in solar array and array deployment and develop risk reduction

strategies

 Provide CDOT with a guidance manual that will provide basic considerations and requirements to address

CDOT environmental, safety, and operation and maintenance expectations

 Make design and safety guidance recommendations pertaining to highway PV array design, installation,

operation and maintenance