Concrete cracks

This is the entrance to my driveway. You can see where the concrete meets the asphalt it has begun to crack. This photo is actually several years old and the cracks are much worse now - giving us a bit of a bump when we drive in or out of the space.



Since this picture grew some sort of grass had taken a hold in the cracks. I think it probably made them worse, but at the same time the grass itself provided a little bit of a ramp and a smooth ride up.

I've seen plants intentionally planted in spacers between concrete slabs, and also artistically planted in naturally occurring cracks.

I'm wondering whether I could get away with planting something like the grass but that maybe doesn't rip the concrete apart as much with its roots, but then is also tough enough to be driven/walked over.

A few searches suggested various thyme varieties for cracks in walking paths... Somehow I don't think thyme will give much cushion though. I was pondering some variety of moss, but it might encourage erosion too.

Any thoughts or ideas?

I could just have more concrete laid down... but I hate concrete.

Does moss grow in your part of the world?

I generally feel that stuff growing in cracks makes the cracks worse.  

If I really wanted something growing in the cracks I would want to grow moss.

I think a lot of different elements are in play here. For starters, why do cracks form in the first place? Some sort of shifting, settling, or upheaval occurred. Any substantial solid pathway exposed to the elements is generally broken up into chunks so they break at the predetermined seams like graham crackers. Much like graham crackers, if the seams aren't deep enough you still end up with jagged cracks.

We can see in the pic there is a crack with no seam at an intersection between the road and the driveway. There is always going to be movement at that point. You can either clean it up into a uniform seam with a flexible buffer such as a synthetic rubber or plants, try to fix it with something inflexible which will either fail or move the failure point to something adjacent, or leave it as is.

I highly doubt the grass in the cracks are the cause of any of the major problems with the current cracks. A lack of seams, possible larger roots, weight, erosion, or heating and cooling are all factors that seem to be much stronger than the roots of many smaller plants. You could try looking at local buildings that are older and have seams with stuff growing in them. If they still look uniform after many years then they are probably a good local plant worth trying out. I would stick to that method vs buying something that may not be well suited to my climate.

I would mostly concern myself with any trees that may be close by. If roots are causing the upheaval they They will likely continue to do so, and if the tree dies for whatever reason, that root may slowly rot and leave a void. Ideally you would heavily prune back the tree and keep it cut back to discourage it from growing excessive roots that could cause further damage.

Every time I've fixed a crack like that I put two lines on the ground that are parallel and lined up with something (In this case the road) so the entire crack fits inside, and then grind away at it with a masonry blade until I have a large V-shaped groove cut. Most people don't want any 'weeds' and elastomeric caulk works well. You could easily add sand and whatever suitable plants into the groove as the transition. Scoop it out every couple years, do any touch up grinder work needed to keep the transition lined up, and replant. If anything has roots that are too aggressive, you can remove it and replace it before it becomes problematic. You could also just sweep it clean and chisel off the high points, but I find most people like the uniform look of a consistent seam so I usually recommend spending the time to cut a groove into it.