Yerevan is a common second city on a Georgian itinerary and an easy one to plan badly. It is close enough to look like an afternoon and far enough to eat a day, and the three ways of covering the distance differ by more than price.
The road distance is roughly 280 kilometres. The crossing is at Sadakhlo on the Georgian side and Bagratashen on the Armenian, about 75 kilometres south of Tbilisi by road, on the S7, open around the clock.

The overnight train, which is a decision about sleep
There is a sleeper service between the two capitals, and it takes a little over ten hours. It runs nightly in the summer months and every second night the rest of the year, so the first thing to check is whether it runs at all on the date you want. A detailed account of the service is more current than anything we could keep accurate here.
Ten hours for 280 kilometres is not a transport decision. It is a hotel decision: you are buying a bed and arriving in the morning. Travellers who enjoy trains love it. Those who do not sleep sitting up arrive at seven in the morning having lost the day they were trying to save.
The marshrutka, which is the real competition
Shared minibuses run the route in about five to six hours and cost very little. They leave when they fill rather than when the timetable says, which in July means the first departure goes early and the third goes whenever it goes.
This is the honest budget answer and most travellers should take it. The cost is the border: you cross with the vehicle, which means your crossing takes as long as the slowest passport in the van. On a quiet Tuesday that is quick. On a summer Saturday it is not.
The car, which is about the border and the stops
Five hours of driving, roughly: about an hour and a quarter from Tbilisi to the crossing, the wait at the crossing itself, and about three hours from Bagratashen down to Yerevan.
The reason to pay for this is not speed; the marshrutka is barely slower. It is that the day becomes yours. The route passes Haghpat and Sanahin, two monasteries that most people see as a photograph after they have already driven past the turning. A car means those are stops rather than regrets.
It also means the border is three people rather than eighteen. At Sadakhlo, waits vary by day and season, so check current reports before planning, as the road manual for the crossings advises.
Where we fit in
Most of the people we drive arrive by air, and a car to Yerevan is not a standing service of ours. Travellers who cross into Armenia overland mostly do it in their own car, by train or by marshrutka, and for most of them that is the right call.
If your trip does need a car to the border, ask when you book, and we will tell you in writing whether we can do it on your date before anything is confirmed. Where we do come in is the Georgian side of the trip: the arrival in Tbilisi, and the days before and after Yerevan, in any of the cars we run.
Which one for which trip
Going for two nights with a suitcase each. Marshrutka or train. The car is not buying you much.
Going with a reason to be in Yerevan at a particular hour. Car. This is the only option where the arrival time is a number rather than a hope, and the same argument that makes a chauffeur the right call when the day has a deadline applies to a border as much as to a flight.
Going as part of a longer regional trip. Plan the Georgian days as a multi-day engagement and the crossing as its own leg, because the return and the days either side are the same conversation.
Flying in and going straight on. Reconsider. A guest landing at Tbilisi after a long haul and continuing five hours south the same day arrives in Armenia having seen a border post. A night in Tbilisi first is the better trip, and what the first day actually costs is small against losing the second one.
What to carry
A passport with six months of validity and, if the nationality needs a visa, one arranged in advance rather than left to the border window. Cash in dram for the first hours, because the ATM situation at the crossing is unreliable on both sides. And the address of the first night, written down, because mobile data around the crossing can be patchy.
Whoever drives the crossing will need nationality and passport details on top of the standard booking brief, and they matter here in a way they do not for a hotel transfer.
The arithmetic of the day
About an hour and a quarter to the crossing, the wait at both sides of it, and roughly three hours down to Yerevan. Call it five hours door to door, more with a stop at Haghpat or Sanahin, against six or more by marshrutka at a small fraction of the price.
Both of those are true at once, which is the whole point of this piece.
For the Tbilisi days either side, or to ask about a car to the border on your date, write to booking@soitblack.com.