Hello there! This is a challenge! It's rather hard to translate texts such as songs and poems from Icelandic because of the tendency to "create" new words or simply because they don't even use Icelandic as people would naturally speak most often...
Here is a veeeeery rough translation of the text... I don't doubt someone else could do better so until then... I hope this helps at least somewhat :)
Áfram veginn í vagninum ek ég
Forward the road I drive in the car
Inn í vaxandi kvöldskugga þröng
Into to growing evening shadows (þröng gives the sentence a meaning as if the shadows are pushing through a narrow slid, if that makes any sense at all)
Ökubjöllunnar blíðróma kliður
This sentence is hard to translate but he is talking about how nice and relaxing the sound of the car is... (sometimes cars are called bjöllur in Icelandi, especially little cars, so this ökubjöllur is more of a "different" way to call cars)
Hægur blandast við ekilsins söng
Here he is still talking about the sound of the car and how it melts to a widows song
Nú er söngurinn hljóður og horfinn
Now the singing is silent and gone
Aðeins hljómar frá bjöllunnar klið
Just the sound of the car can be heard
Allt er hljótt yfir langferða leiðum
Everything is silent over long-to-go path/way (feels like he's on a long road trip)
Þess er leitar að óminni og frið
The one that seeks (óminni is not a word that is used, it's something that the songwriter made... that is acceptable in icelandic literature it's aphenomenon called "skáldaleyfi" or something :D ) and peace.