Invitation to the police hearing as accused

Hello, I need your advice. I have received the following letter from the police: They are summoned for questioning as accused person. The hearing takes place on 28.09 and concerns the criminal proceedings for gross violation of traffic rules – speed crossing on 20.07 as possible / presumed handlebar. The height of the speed crossing was not specified. The above section is the original text of the letter. This letter has made me insecure. I am dependent on the car for my job. I already thank you for your help and advice.