There are 64-bit universal or almost universal hash functions, like CLHASH or VHASH:
Can we create secure 256-bit hash function by concatenation of this hash functions (by using different key for every function)? Similarly like authors of ECHO hash did based on AES (the only paper I found about this is "ASIC Evaluation of ECHO Hash Function").
In fact VHASH family has been proposed for cryptographic applications, and specifically message authentication VMAC:
I think the same idea was behind CLHASH, because otherwise what is the point of proposing 64-bit hash function in 2015? But these functions seem to be very efficient, so why authors didn't go step further and did not propose 256-bit hash functions (especially computed in parallel), which may be then possibly in line with modern stardands of security?