Station dwell time is an important aspect of the day-to-day operation of trains as it can have a substantial effect on the punctuality of trains. A small delay at one station increases the risk of a train arriving late at a subsequent station, and can cause knock-on effects in heavily utilized networks. One of the main causes of dwell time delays can be found in the way passengers distribute themselves between the doors when boarding and the formation of queues around the door of a train. Dwell times are difficult to schedule upfront, leading to a high frequency of dwell time delays. Whilst scheduling longer dwell times could ameliorate the problem, it would negatively impact track capacity as trains remain stationary for longer. Another way to reduce the risk of dwell time delays is to influence passenger's behaviour to reduce its stochasticity and impact on dwell times. This study aims to investigate such an approach by evaluating the effect of a sticker-based intervention which marks the location of train doors and indicates where passengers should stand on 1) the spread of boarding passengers, 2) the passenger flow rates, and 3) the difference in alighting and boarding times between the doors of a train.