These zestful letterforms are from Georg Salden’s Daphne. It’s great to spot this posh typeface in a very down-to-earth use, on the van of a Berlin plumbing and heating service. Bulst was established in 1979. Chances are the logo dates from the same year.
Daphne goes back to a piece of broad-nib pen calligraphy that Salden did for a hat shop in Düsseldorf in the 1960s. It was releases by Berthold Fototypes around 1970. From 2011 on, Salden worked on a digital OpenType version of Daphne, together with his younger colleague Ludwig Übele. Salden “wrote a large number of pages with a very small nib […] in order to rediscover the rhythm of the motion used at the time”. This calligraphic exercise resulted in Daphne Script. Both the reworked Daphne and its slender spinoff are available from Typemanufactur.
The letterforms on the van apparently are from the original phototype Daphne: In the new digital version, the split ‘r’ and the ‘u’ with distinguishing hook (not an umlaut!) had to go. ‘J’ has been shortened, the counters were enlarged, and ‘g’ got a square terminal. The signature swashes are still there, of course — including the terminal ‘t’. See them all in the Daphne User Manual (pdf).