Better than it being in the ocean

On the whole plastic roads seem to show superior durability and longevity to their traditional brethren- but there are caveats. The mix of plastics used and concentrations plays a big part, and almost any plastic road made or engineered poorly will do poorly different types of plastics tend to melt differently and when they are mixed and cool- can separate or cause imperfections. Sorting recycled plastic by specific type has no efficient mechanical means, and countries where labor is expensive it is prohibitive to have humans do the work for cost reasons. So many formulas rely on mixes which might not be ideal, or might not be able to be sourced in high enough “purity” and consistency for mass scale demands.

Since the technology is so new it is still under tested. There is no long term data on performance, and such roads could degrade in a non linear fashion theoretically long term over decades. Meaning they’d need little or no repair right up until failure. Repair of such roads if needed may also be more complex and involve knowing and having access to the correct types or blends of plastics. Long term that could be a problem as common types of consumer plastics become obsolete or less widely available due to changes made in manufacturing or legality of plastics or other factors.

The use of such plastics for heavy duty loads is also a question- how they handle large heavy truck traffic, things mentioned such as road salts and thaws etc. There also are no studies I am aware of as to the way such plastic roads impact vehicle traction (especially in various conditions,) or west of components like tires. Some substrates used in road building cause tires to wear faster or slower and thusly the type of road driven on can accelerate or hinder the need to replace tires more frequently. Even a small wear increase on busy roads has tremendous cost and environmental impacts multiplied by the traffic volume.

There are also other environmental concerns. Plastics do not “break down” the way other things tend to. A sheet of plastic left in nature will “disappear” to a casual glance possibly in only months or years. But the plastic doesn’t chemically change. It just breaks into smaller and smaller pieces which are more easily invested by plants or animals, spread easier, and are harder to remove from the environment. Plastic “stays plastic” even when broken down to the molecular level unlike other common substances which chemically become other elements

In the case of plastic roads that raises concerns that as the roads age and are weathered, as water erodes at them or as they become damaged- they may release micro or nano plastics into the environment. Most plastics will “remain plastic” on a chemical level for hundreds or thousands of years unless engineered to do otherwise- which the plastics recycled for rape use primarily are not.

So the technology has a lot of promise, but it remains untested and has many concerns to be answered. MacReber’s formulation supposedly does’t releases microplastics. But that again remains to be seen long term and by environmental study.

Thank you @guest_ I really appreciate you taking the time to post all of this information. Interesting read and you helped me learn something today

My pleasure. And thank you for appreciating it. I hoped someone might.