diff --git a/code/sql/schema.sql b/code/sql/schema.sql
index f6c2cbc..c778e3c 100644
--- a/code/sql/schema.sql
+++ b/code/sql/schema.sql
@@ -138,6 +138,9 @@ CREATE TABLE waze.roads
   "name"                            VARCHAR(100) NOT NULL
 );
 
+ALTER TABLE waze.roads
+  ADD CONSTRAINT roads_unique_combo UNIQUE(value, name);
+
 CREATE TABLE waze.alert_types 
 (
   "id"                              SERIAL PRIMARY KEY NOT NULL,