Kassel kerb

Since the 1980s, the Association of German Transport Companies invested into the design for a new standard bus, the "Standard-Linienbus II", with the second-generation Neoplan N 416 from 1982 to find wider acceptance.

Shortly later, MAN's competitor Daimler was designing the Mercedes-Benz O405 in 1984 to fit with the new Standard-Bus requirements, and this model spread quickly in the market in the late 1980s.

Based on the Standard-Bus model, a number of variants were developed by their respective manufacturers – here, it was the Kässbohrer Setra S 300 NC to show the first a low-floor version in 1987 that was sold since 1989.

Daimler began to derive the low-floor version of its successful model in its Mercedes-Benz O 405 N, that was produced since late 1989, and which proved to be of a robust design in the following years, leading into rising production numbers.

The resulting prototypes of ADtranz GT6N were delivered in 1990 and mass production started in 1992 with the first batches entering service in Berlin, Bremen and Munich in the following years.

In 1996, the DIN, the German Institute for Standardization, issued the DIN 18024 part 1 ("Barrierefreies Bauen – Teil 1: Straßen, Plätze, Wege, öffentliche Verkehrs- und Grünanlagen sowie Spielplätze; Planungsgrundlagen" / Barrier-Free Design – Part 1: Streets, Places, Roads and Recreational Areas; Planning Basics), updated in 1998.

The Dresden public transport company gives the following reference data:[7] The original Kassel kerb had been designed for a height of 16 cm above street surface.

However the remaining gap turned out to be an obstacle for disabled persons on wheels that required often to ask for help / the usage of a ramp enabled by the bus driver.

The United Nations Convention on the Rights of Persons with Disabilities was enacted in 2009 in Germany which led to a reevaluation of the bus kerbs.