How did the Reservation of Separate Amenities Act affect black South Africans' lives?

In 1953, the Reservation of Separate Amenities Act was passed in South Africa. When talking about the impact of this legislation, it might be helpful to break it down into different categories.
Socially, for example, the Act sought to limit the amount of contact between different racial groups. As the other educator mentioned, this meant that black and white South Africans used different public facilities like toilets, taxis, and elevators—even schools and churches. The only exceptions to this Act were public roads and streets: everything else was segregated.
This separation also had an economic impact on black South Africans. Because of the segregation, they did not have access to the same caliber of schools, university educations, or employment opportunities as white South Africans, which affected their economic status. Remember that the whole point of this law was to reinforce the idea of white supremacy, not to improve the lives of black South Africans.
Therefore, the quality of education and employment provision for black South Africans were inferior to that of white South Africans. This also links into the cultural impact of the Act: it made clear to everyone in South Africa that white culture was dominant and anything else was considered inferior.
For more information and context, see the reference link below.

The Reservation Separate Amenities Act was a piece of Apartheid legislation that allowed the South African government, led by a white minority, to state that certain public facilities were for the exclusive use of one race group. This meant that facilities, from public benches and toilets to beaches and public transport services, could be designated for use only by white people. The words "slegs blankes," which is Afrikaans for "whites only," were commonly seen on signposts around South Africa during the Apartheid era.
This act was designed to keep black people and white people apart. Working hand in hand with this act were other pieces of despicable legislation like the Group Areas Act, which dictated where people of different racial groups could live and work, and the Prohibition of Mixed Marriages Act, which forbade any white person from marrying a black person.