14.10.11 Traffic Control Devices

DDIs require clear traffic control devices to guide drivers through the interchange. The four main objectives of traffic control devices in DDIs are:
  • Priority –
     describes which movement has the ROW;
  • Directional guidance –
     informs drivers about upcoming turning movements;
  • Lane choice –
     communicates to drivers which lane to choose prior to entering the DDI; and
  • Information –
     about other aspects of the interchange. Care must be used when providing informational signs to avoid distracting drivers.
Refer to
NCHRP Report 959
for more information on traffic control devices. The
TMUTCD
remains the primary source for traffic control device standards.