Summit School Services

Durham School Services school bus
Parent	I Squared Capital
Founded	1917
Headquarters	27755 Diehl Road Warrenville, Illinois
Service area	United States and Canada
Service type	School bus contractor
Fleet	14,000+ buses (2025)
Website	summitllc.com

Summit School Services is a North American school bus contractor headquartered in Warrenville, Illinois. Founded in 1917 as Durham School Services, the company became part of National Express Group in 1999 and was acquired by I Squared Capital in 2025. The company provides contracted student transportation services throughout the United States and Canada through operating brands including Durham School Services, Petermann Bus, and Stock Transportation.

Summit School Services is one of the largest contracted student transportation providers in North America, operating a fleet of more than 14,000 school buses.^[1]

The company traces its origins to 1917, when C. M. Durham began providing student transportation services in California's San Gabriel Valley using a fleet of three buses.^[2]

Over the following decades, the business expanded throughout the western United States and became known as Durham School Services, growing into one of the largest providers of contracted student transportation services in the country.^[2]

In August 1999, British transportation company National Express Group acquired Durham Transportation Services for approximately US$175 million.^[3] At the time of the acquisition, Durham operated approximately 3,500 buses and transported more than 430,000 students daily. The acquisition made National Express the third-largest school transportation contractor in the United States.^[4]

National Express continued expanding its North American student transportation operations through acquisitions. In 2000, the company acquired School Services & Leasing, then the second-largest school bus contractor in the United States.^[5]

In 2002, National Express acquired Canadian operator Stock Transportation, establishing a major presence in the Canadian school transportation market.^[6]

In September 2011, National Express announced the acquisition of Petermann Partners for US$200 million. At the time, Petermann was the fifth-largest student transportation provider in the United States, operating approximately 3,351 vehicles across 10 states.^[7][8]

The acquisition was completed in May 2012 following review by the United States Department of Justice, which required the divestiture of transportation contracts in Texas and Washington to address antitrust concerns.^[9][10]

In April 2025, Mobico Group announced an agreement to sell its North American school bus division to infrastructure investment firm I Squared Capital for an enterprise value of up to US$608 million.^[11]

The transaction was completed on 14 July 2025 and included Durham School Services, Stock Transportation, Petermann Bus, and related student transportation operations throughout North America.^[12]

Following the acquisition, the organization adopted the corporate name Summit School Services, while continuing to operate established regional brands including Durham School Services, Stock Transportation, and Petermann Bus.^[13]

National Express expanded its North American student transportation operations through a series of acquisitions that formed the foundation of what later became Summit School Services.

Year	Company	Significance
1999	Durham Transportation Services	Established National Express's U.S. school transportation operations.[14]
2000	School Services & Leasing	Expanded National Express's position in the U.S. student transportation market.[15]
2002	Stock Transportation	Established a major operating presence in Canada through a C$170 million acquisition.[16]
2012	Petermann Partners	Expanded operations throughout the Midwestern United States.[17]

Summit School Services operates through a number of regional transportation brands in North America.

Durham School Services serves as the company's primary operating brand in the United States and traces its history to the original Durham transportation business founded in California in 1917.^[2]

Petermann Bus operates primarily in the Midwestern United States and became part of National Express through the acquisition of Petermann Partners in 2012.^[18]

Stock Transportation operates in Canada and was acquired by National Express in 2002.^[19]

Following the acquisition by I Squared Capital in 2025, the organization adopted the Summit School Services corporate identity while retaining its established regional operating brands.^[20]

Summit School Services provides contracted student transportation services throughout the United States and Canada. The company operates through several regional brands, including Durham School Services, Petermann Bus, Stock Transportation, and other affiliated operating companies.^[21] The company provides transportation services for public and private school districts under long-term service contracts. Operations include daily route transportation, special-needs transportation, extracurricular transportation, and transportation management services.^[22]

Prior to its acquisition by I Squared Capital in 2025, National Express School operated a fleet of more than 14,000 school buses throughout the United States and Canada, making it one of the largest contracted student transportation providers in North America.^[23]

The company has participated in the deployment of electric school buses in partnership with school districts throughout North America. Durham School Services was among the transportation providers selected to receive funding through the United States Environmental Protection Agency's Clean School Bus Program, which supports the replacement of older diesel-powered school buses with lower-emission and zero-emission vehicles.^[24]

On November 21, 2016, a school bus operated by Durham was involved in an accident which left six students dead in Chattanooga, Tennessee. The driver, Johnthony K. Walker was charged with five counts of vehicular homicide. The investigation revealed that though the driver was not intoxicated, he was speeding and had strayed from the assigned route.^[25] Walker had been involved in an accident two months prior, and had his drivers license suspended in 2014 for failure to show proof of insurance.^[26]

• Official website