A new method called MXD was developed to more accurately estimate traffic from mixed-use developments. The conventional method overstates vehicle trips generated and understates transportation and air quality benefits. MXD analyzes household travel surveys from 239 mixed-use sites and found that mixed-use developments reduce traffic through diverse on-site activities, walkable and transit-accessible locations, and central locations with shorter trip lengths. The traffic reductions shown by MXD can demonstrate that conventional methods may exaggerate roadway impacts and the need for mitigation.

1. FOR IMMEDIATE RELEASE
JUNE 9, 2011
For more information:
Alicia Clark, Corporate Communications Specialist
925-977-3241
a.clark@fehrandpeers.com
A Better Method to Estimate Traffic Generated by Mixed-Use Developments
WALNUT CREEK, CA. --
Sustainable developments including mixed-use, infill, and transit oriented developments (TODs) are becoming
increasingly popular. Conventional methods overstate the number of vehicle tips they generate, and therefore
understate their transportation and air quality benefits. The new MXD (mixed-use development) method by Fehr
& Peers accurately captures the trip-reducing benefits of mixed-use development projects, and is used throughout
the U.S. to help developers, public agencies, and the public to quantify these trip reductions.
Current methods of traffic impact analysis, which rely on rates and adjustments from the Institute of
Transportation Engineers (ITE), are believed to understate the traffic benefits of mixed-use developments (MXDs)
and potentially overstate potential roadway impacts because they don’t fully account for the interactions between
land uses or the surrounding built environment. A national study for the US EPA, performed by a team composed
of Fehr & Peers and academic researchers developed a new methodology to more accurately predict the traffic
impacts of MXDs. The study evaluated household travel surveys from 239 mixed-use developments in Seattle,
Portland, Sacramento, Houston, Atlanta and Boston and found statistical relationships between site
characteristics and the amount of vehicle travel generated in and out of the site. MXDs were found to reduce
traffic impacts relative to single-use suburban development, due to the following key factors.
• Diverse on-site activities that capture a large share of trips internally.
• Placement within walkable areas with good transit access that generate high shares of walk and transit
trips.
• Central locations that reduce trip lengths.
The potential vehicle trip reductions from MXDs were significant enough to demonstrate that conventional trip
generation methods could exaggerate roadway impacts and the need for mitigation including higher impact fees,
exactions, and negotiated payments than should be the case. These factors could also contribute to potentially
discouraging development of otherwise desirable projects.
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transportation. The firm has earned a reputation for successfully completing complex and controversial projects
on time and within budget. Fehr & Peers’ mission is to empower every employee to develop effective and
innovative transportation solutions that improve communities. www.fehrandpeers.com.
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