The transportation infrastructure industry is comprised of a number of stakeholders. 

Generally public organizations such as the Federal Government, the Province of Ontario and its ministries and agencies, including Ministry of Transportation of Ontario, Infrastructure Ontario and Metrolinx, municipalities, both Upper and Lower Tier. Publicly traded owners include CN and Canadian Pacific Railway.

The role of the infrastructure owners involves:
1.  investing in and developing infrastructure;
2.  providing infrastructure services to customers;
3.  maintaining and operating infrastructure.

General Contractor
A general contractor is responsible for providing all of the material, labor, equipment (such as engineering vehicles and tools) and services necessary for the construction of the project. The general contractor hires specialized subcontractors to perform all or portions of the construction work.

Responsibilities may include applying for building permits, securing the property, providing temporary utilities on site, managing personnel on site, providing site surveying and engineering, disposing or recycling of construction waste, monitoring schedules and cash flows, and maintaining accurate records.

A subcontractor is a company or person who is hired by a general contractor to perform a specific task as part of the overall project and is normally paid for services provided to the project by the originating general contractor.

Engineers design materials, structures, and systems while considering the limitations imposed by practicality, regulation, safety, and cost. Civil engineers focus on the construction of large systems and structures, such as roads, bridges, public transit.

Product & Service Provider
Companies providing a wide range of good and services to the transportation infrastructure industry, including but not limited to, materials, supplies, equipment, professional services.

Industry Association
An organization founded and funded by businesses that operate in a specific industry. An industry association participates in activities such as advocacy, promotion, education and publishing. Associations may offer other services, such as producing events and conferences and networking.