Can a highway or any public works project be racist? Absolutely, but there is needs to be some sort of burden of proof for me to be comfortable with that conclusion. Some projects overtly were influenced by racism and classism, but that is certainly not a blanket label I’m willing to apply to all past infrastructure projects.
This is my view - except for racism isn't the same as classism, though there is an overlap between race and class. Arguably the issue with highways is classism, rather than racism - the areas where freeways were successfully driven through were lower class 'slums', and the higher class areas were able to block them - rather than specifically targeting black areas.
There's an issue where focussing on race (especially in the UK, where the race issue is more disconnected from the class issue, and there's a big issue with classism) is that the white lower classes are overlooked, exacerbating the classism that the left is meant to care about as being bad. And worse higher class non-whites can be seen as oppressed and in need of help, with the white lower classes as oppressors in need of punishment, exponentially making the classism problem far worse.
You know, by this so-called "logic" if our highways can be racist, so can our railroads.
I remember reading, as a kid, a children-focused history book on the Victorians. When they built the approach to Kings Cross station in the early 1850s, they demolished a cemetery and a load of slum housing. With the cemetery (which wasn't entirely higher class people) they sought permission from the families to move the bodies and found a place to rebury them. With the people in the slums, they just evicted them and razed it to the ground.
Obviously London in the early 1850s was 99% white, and it was possibly the pinnacle of Britain not being racist (Darwin hadn't published so the racism that came off the back of that didn't exist, and the horrors of the slave trade had been thrown off - instead Britain was waging war against those trading slaves), but the same approach in the 60s in the US would have certainly raise 'it was racist' heckles nowadays.