Accumulation on the boundary for one-dimensional stochastic particle system

We consider infinite particle system on the positive half-line moving independently of each other. When a particle hits the boundary it immediately disappears, and the boundary moves to the right on some fixed quantity (particle size). We study the speed of the boundary movement (growth). Possible applications - dynamics of the traffic jam growth, growth of thrombus, epitaxy. Nontrivial mathematics is related to the correlation between particle dynamics and boundary growth.