Manila Metro Rail Transit System, Manila, Philippines

Blue Line (Cleveland) (light rail), Cleveland, Ohio

San Diego Trolley, San Diego, California

Sheffield Supertram Blue Line, United Kingdom

Blue Line (Chicago Transit Authority), Chicago, Illinois

Blue Star Line, a shipping line

Market-Frankford Line, Philadelphia, Pennsylvania

Scarborough RT (TTC), Toronto, Ontario

LACMTA Blue Line, Los Angeles County, California

Hong Kong MTR Island Line, Hong Kong, China

Blue line (ice hockey), the line between center ice and each team's zone

The Thin Blue Line

Blue Line (MBTA), Boston, Massachusetts

Bangkok Metro, Bangkok, Thailand

Expo Line, Vancouver SkyTrain

MAX Blue Line, Portland, Oregon

Tomorrowland Transit Authority, Walt Disney World, Florida

Viva Blue, York Region, Ontario, Canada

Rapid Ride Route 790 Blue Line, Albuquerque, New Mexico

The Blue Line (New York State), delineates the Adirondack and Catskill parks of New York's Forest Preserve

Blue Line (Lebanon), the UN drawn line between Israel and Lebanon

RER B, Paris, France

Blue Line (Washington Metro), Washington, DC

Dublin/Pleasanton - SFO/Millbrae Line, San Francisco Bay Area

Yotsubashi Line (Osaka), Japan

Seoul Subway Line 4, South Korea

Shanghai Metro Line 8, Shanghai, China

Line 10 (Madrid Metro), Madrid, Spain

Tokyo Metro Tozai Line, Tokyo, Japan

Barcelona metro line 5, Barcelona, Spain

Kurenivsko-Chervonoarmiyska Line, Kiev, Ukraine

Line 5 Blue (Montreal Metro), Montreal, Quebec

H Line (RTD), Denver, Colorado

Blue Line (Yokohama) (also called Lines 1 & 3), Yokohama, Japan

Indraprastha - Dwarka Sub City Line, Delhi, India

Blue Line (airline), based in France

Saltovskaya Line, Kharkov, Ukraine

Lyon Metro Line B, Lyon, France

Moskovskaya Line, Minsk, Belarus

Blue Line International, a ferry line

The "blue line" mark on an airspeed indicator for a multi-engine aircraft indicating V_YSE, the speed for best rate of climb with the critical engine inoperative.

Dark Blue Line, London Underground, United Kingdom

Light Blue Line, London Underground, United Kingdom

Blue Line, Stockholm Metro, Sweden

Moskovsko-Petrogradskaya Line, Saint Petersburg Metro, Russia

Blue Line (Dallas Area Rapid Transit), Dallas, Texas

Sacramento Regional Transit District Blue Line (Watt/I-80-Downtown-Meadowview)