Lilyka, that's a lovely prayer!
We have rosaries in our vehicles (started when we were given my FIL's old car and he left a rosary in the glove compartment).
I am a nervous driver too, and I find saying a rosary under my breath really helps. I use my fingers on the steering wheel to count off the decades.
We used to have a St. Christopher prayer card and my dd would read the prayer - got lost a while back though.
Now my kids chant the following (extremely modified) version of the St Christopher prayer we used to read when we buckle up:
1-2-3-4
Jesus keep us safe once more!
5-6-7-8
Jesus keep our path real straight!
9 and then 10
Keep our car safe till we pray this prayer again!
RED SEA!!!
[short for "Please guide us safely through traffic as God guided Moses and the Israelites across the Red Sea"]
Not really poetic as travel traditions go, but its all ours

My dd gave me a Moses action figure as a bit of a joke and I stuck it on my dash to remind me of the Red Sea. I am careful not to think of it like I do the rosary, as a sacred object in itself, because Moses would probably have hated that (the Golden Calf incident really enraged him). It helps me to visualize the traffic parting before me

and makes me smile.
I have been in some hairy situations in the last year or so, driving through horrible snowstorms, near the eye of tornadoes more than once. When I am really frightened and can't see the road ahead of me, I feel the spirit of my dad and my FIL as though they were in the car with me -- In life, they were both EXTREMELY safety conscious people and excellent drivers and I always felt safe with them behind the wheel.
Follow Mothering