According to the ISO 3166-2 standard of the International Organization for Standardization, the geocodes "KAZ" and "KZ" officially designate the Republic of Kazakhstan. These codes are widely used in Internet domains, government documents, accounting documents and car license plates. They are recognizable both inside and outside the country. In this regard, Kazakhstan has approved the "KAZ" and "KZ" indexes for highways of international and national importance.
The KAZ index is assigned to 23 highways passing through several regions. For example, the road between Astana and Almaty through Karaganda received the KAZ01 index, and the Astana – Kokshetau route (with a detour) – Petropavlovsk – the border of the Russian Federation (Zhana Zhol checkpoint) is designated as KAZ02.
The KZ index is used for 88 roads of national significance located within the same region. For example, the Kandyagash – Emba – Shalkar– Irgiz road in Aktobe region received the index KZ04-02, where "04" indicates the region, and "02" indicates the serial number of the road within the region. The Merke – Shu – Burylbaytal road in Zhambyl region is designated as KZ08-04, where "08" denotes the region, and "04" is the number of the road within the region.

The highway indexes assigned under international agreements, such as "E" and "AN", will remain unchanged, which ensures consistency in the international transport system and convenience for transit traffic.
The list, names and indexes of highways can be found at the link: https://adilet.zan.kz/rus/docs/V1500011402 .
The development of a new indexing system was carried out by KazdorNII JSC.
The road signs will be updated gradually as planned work is carried out and worn-out elements are replaced.

No additional funds are required for this, the work will be carried out within the framework of road maintenance.

Source : https://www.gov.kz/memleket/entities/transport/press/news/details/888471