The Wales and Borders network is expected to be busy following the reopening of pubs, cafes and restaurants in Wales for outdoor hospitality.
Passenger numbers have risen to more than 60 per cent of pre-Covid levels at some TfW stations in recent weeks and this has resulted in an increase in anti-social behaviour.
Operational resilience manager Joshua Hopkins said: “Unfortunately there is still a small minority of people who are choosing to put themselves, other passengers and our staff at risk through anti-social behaviour on our services and at stations.
“We will have a strong presence of TfW, security and British Transport Police staff across the network to ensure it remains a safe environment for people wishing to travel.
“People may find there are queuing systems in place or other crowd control measures and it is important people respect and listen to our frontline staff at all times.
“Our staff do have the right to refuse travel if people are abusive or too intoxicated to travel.
“We strongly encourage everyone to follow our Travel Safer advice, check timetables, plan ahead, follow social distancing, wear a mask, unless exempt, and use our Capacity Checker to check if the train is full."
British Transport Police Inspector Richard Powell said: “Our top priority is to keep passengers and rail staff safe. We continue to patrol the network, ensuring those using the railway can do so safely.