Disclosures teach providing data over a vehicle bus, data providing values for a road attribute indexed to points anticipated to be traversed by a vehicle. To compress the data, a server may fit a regression function to the data with coefficients applied to kernels in the function. The server may limit the number of coefficients to reflect a limitation on rate of change imposed on data by the road on which it reports. Similarly, the server may limit one or more numbers of bits encoding the coefficients in a message transmitted on the vehicle bus, reflective of a limited range of potential amplitudes for data imposed by the road. A client may maintain a copy of the kernels and retrieve the coefficients from the message. The client may estimate future values of the road attribute by evaluating the coefficients applied to the kernels, which may, in some examples, be Gaussian.