Question

do blood cells travel quick

Answer 1

Yes

Answer 2

In a resting human being as your blood leaves it is travelling at bout 1 mph or 450 mm per second, as it moves into ever smaller arteries it becomes slower and slower until in the finest capillaries it is travelling at only 0.5 mm per second, slow enough for oxygen molecules to get off and carbon dioxide to get on board the red corpuscles. Then in returning to the heart it picks up speed again as it enters the larger veins put its top speed on the return journey is about half that it started out with. At this rate it takes less than a minute for you blood to travel right around your body and back to your heart again...
http://www.earthlife.net/mammals/blood.html