D300 is a state road connecting A9 with Umag

Umag

Umag is a coastal city in Istria, Croatia.The city hosts the yearly Croatia Open ATP tennis tournament on clay courts.-Geography:It is the westernmost city of Croatia, and the municipality includes Savudrija which is westernmost point of Croatia....

 and D21

D21 (Croatia)

D21 is a state road connecting the Kaštel border crossing and Buje, as well as A9 motorway via D510 state road. The road is long.The road provides connections to several towns and cities in central and western Istria, most notably to Grožnjan, Svetvinčenat and Pazin via roads connecting to...

 state road in Buje

Buje

Buje is a town situated in Istria, Croatia's westernmost peninsula, population 2,979 .Buje was known as the "sentinel of Istria" for its hilltop site located inland from the Adriatic sea. It still commands an excellent panorama. Buje has a rich history; traces of life in the region date back to...

. The road is 12.2 km long.

The road, as well as all other state roads in Croatia, is managed and maintained by Hrvatske ceste

Hrvatske ceste

Hrvatske ceste is a Croatian state-owned company pursuant to provisions of the Croatian Public Roads Act , the county and local roads are managed by county authorities, while the motorways are managed by Croatian Motorways Ltd and other concessionaires.The company is currently administered by a...

, state owned company.

Traffic volume

Traffic is regularly counted and reported by Hrvatske ceste

Hrvatske ceste

Hrvatske ceste is a Croatian state-owned company pursuant to provisions of the Croatian Public Roads Act , the county and local roads are managed by county authorities, while the motorways are managed by Croatian Motorways Ltd and other concessionaires.The company is currently administered by a...

, operator of the road. Substantial variations between annual (AADT) and summer (ASDT) traffic volumes are attributed to the fact that the road connects A9 motorway carrying substantial tourist traffic to Umag

Umag

Umag is a coastal city in Istria, Croatia.The city hosts the yearly Croatia Open ATP tennis tournament on clay courts.-Geography:It is the westernmost city of Croatia, and the municipality includes Savudrija which is westernmost point of Croatia....

, a major summer resort.

D300 traffic volume
Road	Counting site	AADT	ASDT	Notes
D300	2705 Grando	5,284	6,636	The westernmost traffic counting site on D300.
D300	2718 Buje west	6,335	8,571	The easternmost traffic counting site on D300.

Road junctions and populated areas

D300 junctions/populated areas
Type	Slip roads/Notes
	D21 D21 (Croatia) D21 is a state road connecting the Kaštel border crossing and Buje, as well as A9 motorway via D510 state road. The road is long.The road provides connections to several towns and cities in central and western Istria, most notably to Grožnjan, Svetvinčenat and Pazin via roads connecting to...  to Krasica and to Kaštel border crossing to Slovenia Slovenia Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of... . Eastern terminus of the road.
	Ž5070 to Brtonigla Brtonigla Brtonigla is a village and municipality in the north-western part of Istria, Croatia, 6 km southwest of Buje; elevation 141 m. It is close to the A9 motorway. Chief occupations include farming, viniculture and vegetable growing....
	Umag Umag Umag is a coastal city in Istria, Croatia.The city hosts the yearly Croatia Open ATP tennis tournament on clay courts.-Geography:It is the westernmost city of Croatia, and the municipality includes Savudrija which is westernmost point of Croatia....  interchange: A9 motorway to Pula Pula Pula is the largest city in Istria County, Croatia, situated at the southern tip of the Istria peninsula, with a population of 62,080 .Like the rest of the region, it is known for its mild climate, smooth sea, and unspoiled nature. The city has a long tradition of winemaking, fishing,...  (to the south) and to Ž5002 road (to the north) which serves as a short connecting road to D200 D200 (Croatia) D200 is a state road connecting Plovanija border crossing and Buje, as well as A9 motorway Umag interchange via Ž5002 county road. The road is 7.6 km long.The road also provides a connection to Kaštel border crossing via D510 and D21 state roads....  and D510 D510 (Croatia) D510 is a state road connecting D200 near Plovanija border crossing and D21 near Kaštel border crossing, as a part of a series of short roads connecting Kaštel border crossing and A9 motorway Umag interchange...  state roads leading to border crossings Kaštel and Plovanija to Slovenia Slovenia Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of... .
	L50011 to Kršete and Brtonigla Brtonigla Brtonigla is a village and municipality in the north-western part of Istria, Croatia, 6 km southwest of Buje; elevation 141 m. It is close to the A9 motorway. Chief occupations include farming, viniculture and vegetable growing....
	Materada Materada Materada is a village in Croatia....
	Juricani Juricani Juricani is a village in Croatia. It is part of Umag.... L50008 to Čepljani Čepljani Čepljani is a village in Croatia....
	Petrovija L50006 to Vilanija Vilanija Vilanija is a village in Croatia....
	Finida Finida Finida is a village in Croatia....
	Umag Umag Umag is a coastal city in Istria, Croatia.The city hosts the yearly Croatia Open ATP tennis tournament on clay courts.-Geography:It is the westernmost city of Croatia, and the municipality includes Savudrija which is westernmost point of Croatia.... : Ž5002 to Novigrad to the south and Savudrija Savudrija Savudrija is a coastal settlement in northwestern Istria, Croatia. It has developed from a fishing village into a pleasant holiday centre. Savudrija is also the name of the surrounding area in the peninsula.... to the north Western terminus of the road.