Founded in 1964, TTL is an engineering design firm focused on delivering integrated infrastructure solutions for public and private clients. From site and corridor selection to due diligence, design, and construction services, TTL is a trusted partner providing single-sourced custom solutions for complex infrastructure development. With over 450 team members, TTL provides civil design, transportation design, surveying, geotechnical engineering, environmental consulting, CEI, and materials testing/inspection/observation services.