If one bike has a rear rack, you can attach the second bike's front wheel with a bunch of bungies and tow it.
I've done this, and it worked fine.
Now I have a cargo bike, and the towing is simpler:
bicycles.stackexchange.com/users/11445/David Crowell
Walk :) Safest.
I do this from time to time
(usually when one of the kids have 'forgotten' their bike), and find it easiest to do as pr above, but with a little variation.
If the transported bike is lightweight and otherwise allows it, simply 'wear' it as a backpack, putting your arm through the big triangle.
Once it's on, you can determine if it will Work.
Did this once with a racing bike at 7,5Kg.
As the other answers, except I grab the center of the handlebar with palm forward, and then lift the front Wheel of the bike.
This allows me to sit on my own bike more comfortably, and balance is way better since the transported bike doesn't try to steer.
bicycles.stackexchange.com/users/13480/Passing through
If you are reasonably firm at riding one-handed, you can drive them home by riding one of them while pushing/pulling the other one beside you with one hand.
Let's assume that the bike you will ride is called A and the one you push/pull is B .
First decide, which bike is better to be ridden and therefore will be your bike
A and which hand is better to get freed to steer bike B .
Which hand is better will depend on if you will need to change gears and how your brakes are arranged on the handle bars.
Then lean bike B somewhere, e.g. to a tree or wall – putting it on its stand is not so good as it might get complicated to get the stand folded in later.
Also make sure to lean it on with the correct side, depending on your choice of which hand you want to use to steer it.
Finally mount bike
A
and place yourself on the bike beside B .
Now grab either the stem or the center of the handlebar (where it is held by the stem) of bike B , such that you have some steering control over the handlebar if you twist your wrist.
The most complicated part in this is starting as you will have some wobbly moments on the start
and you have to take care not to interfere with the handlebars of both bikes.
Having drop bars (as in your case) will make things a bit easier in terms of interference as they are not that wide and it is easier to keep both bikes separated.
Also you have to take care to not lean onto the wrong bike, as putting your weight on bike B will make it go somewhere more or less unpredictable and you're quite likely to crash.
So only put your weight onto bike A 's handle bar.
Once you have the whole train running, this arrangement is quite fine (albeit a bit clumsy) as long as you don't have to cope with too much traffic (which is given in your case).
However, 5 miles is some piece to ride this way so expect to be somewhat slower than normal and plan to do some pauses on your way as you won't have a very relaxed riding position.
bicycles.stackexchange.com/users/5271/Benedikt Bauer
One possible way is to ride one bike and push the other.
One hand goes to handlebars and front brake, the other grips the second bike by the handlebar stem.
This is slow and clumsy, of course, but if you are able to ride the said route with no hands, you should be able to move both bikes as well.
bicycles.stackexchange.com/users/3927/Vorac
Ghostride it, so long as you're not dealing with high speeds or heavy traffic: http://www.instructables.com/id/How-To-Ghostride-a-Bike/ And make sure you have a soundtrack:
bicycles.stackexchange.com/users/5702/Alan Gerber
Ride one bike, and have a friend ride the other bike.
Once home, give friend a beer and say "thank you, see you tomorrow."
bicycles.stackexchange.com/users/13519/Anonymous Citizen
I'd walk with both bikes - with each hand on their seats, one to the left and other to your right.
Bicycles can be easily pushed and steered when holding them at the seat (in the same manner as you would correct steering when riding without hands, through the balance).
I find it easier than pulling them by the middle of handlebars as others suggest.
Doing so with two bikes at once is tricky, and this is slower than riding; but it's safer and you'd get there in the end with no risk of falling yourself; at worst you'd have to stop and readjust them a few times.
bicycles.stackexchange.com/users/10485/Peteris
Personally I enjoy running as much as riding.
If I could not carry the second bike I would ride one home, run back, ride the other home.
It would take a bit longer and be a great workout....... Presuming 2 bikes @10
km/h
that is about 45-50 minutes (without prangs), or 30km/h (2*16minute) on bikes + 5 minute/km (40 minute) run - 1:15.
bicycles.stackexchange.com/users/3924/mattnz
My friend was able to ride a few miles with a second bike attached to his backpack with a ropes.
You need a wide road for this way of transportation and it can be tricky to tie bike in such a way that it doesn't weights to one side.
Also, you can detach wheels and tie them to the frame, so bike will be more compact.
bicycles.stackexchange.com/users/13486/lexszero
I am contemplating this - fit a "truck bed front fork clamp" to the parcel rack on my electric bike and tow the other bike.
Have to remove the front wheel and strap it on the towed bike's frame.
Possibly could get away with an old front hub sans spokes, and clamp that onto your rack or even the rear seat stay of teh front bike.
Have to watch the clearances of course, left
/right turns as well as up/down.
300mm velcro cableties will be used to strap towed bike's front wheel to the frame.
Edit: I did this and it was not a success.
Complete write up in this answer
bicycles.stackexchange.com/users/19705/Criggie
I need to move two bicycles from work to home. The route is 5 miles long and car free. My only means of transport is to ride one of the bicycles so my question is this: What is the safest way to get both bikes from work to home in one journey? (without some kind of trailer)  The bikes are a Carrera Virtuoso and a Scott Yecora (dropped handlebars)
How to move a bicycle by bicycle
bicycles.stackexchange.com
<commuter><advice>
bicycles.stackexchange.com/questions/24292
bicycles.stackexchange.com/users/11200/nettux
The safest way to transport two bikes is to walk. However, there are other options. One option is to ask a friend to ride the second bike. Another is to ride one bike hoe, run back and ride the other. If riding one'handed is no problem, ride one bike and hold the other with your free hand. Moreover, you could wear the other bike like a backpack. Finally, if one bike has a rear rack, the second bike can be attached to it. The safest way would be to walk while holding both bikes,  get a friend to ride the second bike or take the bikes in two trips. If you are comfortable riding one-handed, you can hold the other by the stem while steering and holding the brakes of the bike you're riding. If the bike is light enough, you can carry it on your back. You could attach the front wheel or fork to the luggage rack of the bike in front, then tow it.
The safest way would be to walk while holding both bikes,  get a friend to ride the second bike or take the bikes in two trips. If you are comfortable riding one-handed, you can hold the other by the stem while steering and holding the brakes of the bike you're riding. If the bike is light enough, you can carry it on your back. You could attach the front wheel or fork to the luggage rack of the bike in front, then tow it.