Transport

I would scope out who would be interested and an idea of max cost ( work it out on 75%) uptake as if you give the cost and it then goes up if people don't do it you would need them to pay more and they may then decline, give them a date to reply by with their interest. We have the same distance away and offered to organise transport at their cost but was not enough uptake to make it worthwhile so decided against it. Most people are happy to travel but also like the convenience of being able to do it under their own steam and have transport in case of emergency (we have a lot of people who have kids that wont be at the wedding) also you would need set times for pick up and drop off which some people find a stress and may want to leave earlier or later. If there are local hotels nearby the venue maybe suggest some to your guests as some people also like to make a weekend of it and will stay nearby