Where to store luggage in Rome
 

I will be traveling into Rome on Saturday June 9th from an overnight train.
I will arrive at 9am, and then have to take the metro to make a tour at the Colosseum at 10am.
My luggage will be with me and I am not sure what to do with it. I have read that the Termni station has a luggage room, but I have seen reviews that the lines were long (over 2 hours!!), but also have seen reviews that it was quick and easy.
My question would be is there another option I have to store my luggage? Does the metro B line have lockers/storage rooms at their stations?
I am very nervous I will miss my tour if I try to store my luggage at the station if the line is long. Maybe the Colosseum or near by has somewhere to store luggage?

Well, let's hope your train is on time. I'm not sure I would have put that much faith in a train timetable.

Are you spending the night in Rome? If so, you could taxi to your hotel, drop your luggage and continue in the taxi to the Colosseum. (You may have to wait in a taxi queue.) If you're not spending the night, I don't think you have an option other than the Termini baggage storage. (You may have to wait in a queue.) Either way, you'd better pray to the travel gods.

Or would it be possible to take a later tour?

There won't be storage in the metro or at the Colosseum. The luggage storage at Termini is down a level.
http://www.grandistazioni.it/cms/v/i...003f16f90aRCRD

There are several places to access the lower level track side so look for a way to go down without having to go all the way to the head of the tracks. After checking your luggage, stay on the lower level to head to the metro entrance.

Have euro ready for the ticket machine at the metro entrance. The Colosseum is only two stops.

Now unfortunately, you'll need 1.50€ to make that short, two-stop run from Roma Termini to the Colosseo... ** http://tinyurl.com/ATAC-increase **