Maricopa County

about mcdot

What is the Maricopa County DOT

The Maricopa County Department of Transportation (MCDOT) Plans, Designs, Builds, Maintains and Operates the County roadway system.


Providing connections that improve people's lives.


  • Service Minded
  • Team Builder
  • Get it done with a smile

Maricopa County has a population of approximately four million, and is the fourth most populous county in the US.  With more than nine-thousand square miles it is larger than seven different states.  The County is administered by a County Manager who reports to the five member Board of Supervisors elected by the public.

View the Department's Organizational Chart

Meet the MCDOT Leadership Team

The Maricopa County Department of Transportation (MCDOT) plans, designs, constructs, operates and maintains roadways within the County’s unincorporated areas. MCDOT is responsible for the operation and maintenance of approximately 2,500 miles of roadway, more than 80 bridges (16 of them greater than 400 feet long) and more than 325 culvert crossings, more than 160 signalized intersections and nearly 35,000 traffic signs. MCDOT’s funding is primarily derived from Highway User Revenue Funds, and other federal and state sources. Maricopa County has a population of approximately four million, and is the fourth most populous county in the United States. With more than nine-thousand square miles it is larger than Connecticut, Delaware and Rhode Island combined.

Jennifer Toth, P.E.Jennifer Toth, P.E.
Transportation Director
County Engineer

Jennifer Toth brings more than 18 years of experience in transportation engineering to her role as MCDOT Director and County Engineer, one of the largest counties in the United States.  Before joining MCDOT in 2014, Jennifer served as State Engineer and Deputy Director of the Arizona Department of Transportation with responsibility for planning, designing, constructing, maintaining and operating more than 6,000 miles of interstate and state highways in Arizona.  She has also worked in the private sector as a transportation consultant.

Jennifer holds a Bachelor of Science degree in Civil Engineering from the University of Houston and a Master of Science degree in Civil Engineering from the University of New Mexico. She brings to MCDOT a passion for public service and meeting the transportation needs of the residents of Maricopa County.

Teresa Welborn, AdministratorTeresa Welborn

Teresa Welborn brings more than 25 years of experience in the government and non-profit sectors to her position as Administrator for the Maricopa County Department of Transportation. She oversees the divisions of Financial Services, Information Technology, Administrative Services, Communications, and Intergovernmental Relations.  Teresa provides experience in program, contract and budget management, strategic planning, process improvement, communications, media relations and community outreach.  Previously, Teresa was with the Arizona Department of Transportation where she served as Partnering Administrator and Assistant Communications Director.  Teresa holds a Bachelor of Science Degree in Finance from the University of Arizona and a Masters of Education degree in Educational Leadership from Northern Arizona University. Teresa is a member of the WTS Phoenix Metropolitan Chapter and serves on the WTS International Foundation Board.

Eng. Division Mgr, Edmund Williams, P.E.Edmund C. Williams, P.E.
Engineering Division Manager

Ed Williams has over 20 years of civil engineering experience. Before joining MCDOT as the Engineering Division Manager in 2012, he worked as a design engineer and project manager on commercial developments and tribal projects for J&K Engineering in Prescott, Arizona. He has also worked at Parsons Transportation Group in Denver, Colorado as well as a number of small local firms in Boulder, Colorado and Prescott, Arizona. Ed earned a Bachelor of Science in Civil Engineering from the Georgia Institute of Technology. He is a member of the American Society of Civil Engineers, Engineers without Borders and the American Public Works Association.

Traffic Mgmt Div Mgr, Nicolaas Swart, P.E.Nicolaas P. Swart, P.E.
Transportation Systems Management Division Manager

Nicolaas Swart has been the Transportation Systems Management Division Manager since 2006. He oversees all aspects of Traffic Engineering and Intelligent Transportation Systems (ITS). He comes to MCDOT with a strong international engineering background. Before joining MCDOT he worked for Associated Engineering (B.C.) Ltd. in Canada and Ninham Shand, Inc. in South Africa. Nicolaas earned his Bachelor of Science in Civil Engineering and his post-graduate degree in Transportation Engineering from the University of Pretoria in South Africa. He is a member of the State Board of Technical Registration of Arizona, the Association of Professional Engineers and Geoscientists of British Columbia, the Intelligent Transportation Society of Arizona and the Institute of Transportation Engineers. He also serves as the Program Manager for AZTech, a partnership of local agencies integrating transportation systems across jurisdictional boundaries through traffic management and ITS solutions.

IT Division Mgr, Roseann Osborn-PerezRoseann Osborn-Perez
Information Technology Division Manager

Roseann Osborn-Perez has worked with the County since 1982. She started her career as a Management Information Systems (MIS) Specialist, working her way up to become the Information Technology (IT) Division Manager. Positions she has held include MIS Supervisor, an Assistant Project Manager and Application/Program Manager with the Maricopa County Health Services Department. As IT Division Manager, she is responsible for evaluating and bringing technology to MCDOT business processes to help departments be more efficient. Roseann earned her Bachelor of Science in Business Administration specializing in Management Information Systems with a minor in Computer Science from Glassboro State College in New Jersey.

Kevin Kottmer, Roadway Maintenance Division ManagerKevin Kottmer
Roadway Maintenance Division Manager

Kevin Kottmer has over 30 years of professional government service, beginning his career at MCDOT as a Summer Aide Intern.  Kevin advanced through several MCDOT positions and Divisions including Operations, Procurement, Engineering, Traffic Management, Project Management & Construction and Real Estate.  Kevin also gained valuable experience working at the Arizona Department of Emergency Management and Military Affairs. Kevin is an active member of the Local Arizona Chapter of the American Traffic Safety Service Association (ATSSA).  Kevin holds certifications including  ATSSA Certified Traffic Control Supervisor and ATSSA Certified Flagger Instructor. Kevin is responsible for Roadway Maintenance, Traffic Maintenance, Maintenance Support and Fleet Maintenance.  He finds great satisfaction in assisting the residents of Maricopa County.

Cynthia Robinson, Administrative Services Division ManagerCynthia Robinson
Administrative Services Division Manager

Cynthia Robinson brings nearly 30 years of experience to her role as Administrative Manager, including serving MCDOT as Customer Service Manager, Security Manager and Facilities Manager. As the Administrative Manager, Cynthia oversees Procurement (Article three and five), Facilities Management, Records Management, Customer Service and Warehouse Management activities for MCDOT. Additionally, she serves as the Custodian of Records and the Legal Liaison with the County Attorney's office. Cynthia holds numerous degrees and certifications including a Master of Public Administration and an Electronic Content Master certification. She is a member of the International Facilities Managers Association, Project Management Institute and many other professional associations. In 2009, Cynthia was awarded the Outstanding Public Works Employee Award from the American Public Works Association.

Alfred Erives, Acting PCI Division ManagerAlfred Erives
Permitting, Construction and Inspections Division Manager
Superintendent of Streets

Alfred Erives brings over 30 years of transportation experience to MCDOT. Since 2013, he has served as MCDOT's Chief Construction Engineer and has managed Roadway Maintenance and Transportation Improvement Plan construction projects. Prior to working for MCDOT, Alfred was employed by the City of Phoenix, Streets Transportation Department where he worked his way up from a Senior Drafting Technician to a Resident Engineer and Project Manager. Alfred holds a Bachelor of Science degree from Arizona State University in Construction Management.

Darrell Funk, Financial Services ManagerDarrell Funk
Financial Services Manager

Darrell Funk has over 15 years of experience in budget and fiscal management as well as experience in strategic planning, process improvement, procurement, purchasing, forecasting and analysis. Prior to working for MCDOT, Darrell worked for the Arizona Department of Economic Security where he served in a variety of positions, including Financial Manager, Business Administrator and Deputy Chief Financial Officer. Darrell holds a Bachelor of Science Degree in Finance from Northern Arizona University and is a Certified Public Manager from Arizona State University.

You can contact MCDOT by either calling the customer service number at the information below or or online


2901 W. Durango
Phoenix, Arizona 85009
(Southwest corner of 29th Ave & Durango)

Phone: (602) 506-8600

Fax: (602) 506-4750

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