Warm air rising off the pavement is an example of convection.
Convection is the process by which heat is transferred through the movement of fluids (liquids or gases). In this case, the pavement absorbs heat from the sun, warming the air just above it. As the air heats up, it becomes less dense and rises, creating a convection current.
Radiation would involve heat transfer through electromagnetic waves (such as sunlight warming the pavement), while conduction involves heat transfer through direct contact between materials. The rising warm air is specifically a convective process.