Emergency services were called to Brentford High Street at 5.17pm on Friday November 17 to reports of a collision between a person and a bus.
The girl was taken to hospital where her injuries were assessed as not life-threatening or life changing. The driver of the bus stopped at the scene.
Roadworks have been in place for several months and one local at the scene said similar incidents are happening more frequently, the MailOnline reports.
A local resident who witnessed the collision told the newspaper: "Roadworks have been ongoing here for many months to narrow the road and build a cycle lane.
"The roads are being made much more dangerous and these kind of accidents are becoming commonplace. Meanwhile the cycle lane is completely empty."
They added: "It is a continuation of the cycle lane work which has already destroyed Chiswick High Road making it much more unsafe, causing many more accidents, collisions and making traffic unbearable.
"It appears that TfL has gone completely crazy."
Footage posted by the resident showed the girl weeping in pain on the road next to a stationary bus.
One person assured her an ambulance is on the way while another insisted she needed to stay lying on the ground.
Roadworks can be seen on the left-hand side of the bus while a sign states the pedestrian crossing is not in use.
Helen Cansick, TfL's Head of Healthy Streets Investment, said: “Safety is our number one priority and our thoughts are with the woman involved in this collision.
"Our work with Hounslow and Hammersmith and Fulham Councils along the Cycleway 9 route is enabling thousands of people to walk and cycle safely and providing sustainable and affordable travel options.
"We monitor all new cycle routes closely and there is no indication from those who witnessed the incident that the works or new cycleway played any part.
"We will continue to work with boroughs along the route to ensure that the new route is safe for everyone travelling in the area, and will respond to any requests for information concerning this incident."